80. If we do not take into account the vibrational motions in the hydrogen molecule at a temperature of 200 TO, then the kinetic energy in ( J) of all molecules in 4 G hydrogen is ... Answer:
81. In physiotherapy, ultrasound with frequency and intensity is used. When exposed to such ultrasound on human soft tissues with density, the amplitude of vibrations of molecules will be equal to ...
(Consider the speed of ultrasonic waves in the human body as equal to Express your answer in angstroms and round to the nearest whole number.) Answer: 2.
82. Two mutually perpendicular vibrations are added. Establish a correspondence between the number of the corresponding trajectory and the laws of point oscillations M along the coordinate axes 
Answer:
1 
2 
3 
4 
83. The figure shows the profile of a transverse traveling wave, which propagates at a speed. The equation of this wave is the expression ... 
Answer:
84. The law of conservation of angular momentum imposes restrictions on the possible transitions of an electron in an atom from one level to another (selection rule). In the energy spectrum of the hydrogen atom (see Fig.), the transition is forbidden ... 
Answer:
85. The energy of an electron in a hydrogen atom is determined by the value of the main quantum number. If , then equals... Answer: 3.
86. .
The angular momentum of an electron in an atom and its spatial orientations can be conditionally depicted by a vector diagram, in which the length of the vector is proportional to the modulus of the orbital angular momentum of the electron. The figure shows the possible orientations of the vector . 
Answer: 3.
87. The stationary Schrödinger equation in the general case has the form 
. Here 
potential energy of a microparticle. The motion of a particle in a three-dimensional infinitely deep potential box describes the equation ... Answer: 
88. The figure schematically shows the stationary orbits of an electron in a hydrogen atom according to the Bohr model, and also shows the transitions of an electron from one stationary orbit to another, accompanied by the emission of an energy quantum. In the ultraviolet region of the spectrum, these transitions give the Lyman series, in the visible - the Balmer series, in the infrared - the Paschen series. 
The highest quantum frequency in the Paschen series (for the transitions shown in the figure) corresponds to the transition … Answer: 
89. If the proton and deuteron have passed the same accelerating potential difference, then the ratio of their de Broglie wavelengths is ... Answer:
90. The figure shows the velocity vector of a moving electron: 
WITH directed... Answer: from us
91. A small electric boiler can boil a glass of water for tea or coffee in the car. Battery voltage 12 IN. If he is 5 min heats 200 ml water from 10 to 100° WITH, then the current strength (in A
j/kg. TO.)Answer: 21
92. A conductive flat circuit with an area of 100 cm 2 
Tl mV), is equal to ... Answer: 0.12
93. The orientational polarization of dielectrics is characterized by ... Answer: the influence of the thermal motion of molecules on the degree of polarization of the dielectric
94. The figures show graphs of the field strength for various charge distributions: 
R shown in the picture... Answer: 2.
95. Maxwell's equations are the basic laws of classical macroscopic electrodynamics, formulated on the basis of a generalization of the most important laws of electrostatics and electromagnetism. These equations in integral form have the form:
1). 
;
2). 
;
3). 
;
4). 0.
Maxwell's third equation is a generalization Answer: Ostrogradsky-Gauss theorems for an electrostatic field in a medium
96. The dispersion curve in the region of one of the absorption bands has the form shown in the figure. Relationship between phase and group velocities for section bc looks like... 
Answer:
1. 182 . An ideal heat engine operates according to the Carnot cycle (two isotherms 1-2, 3-4 and two adiabats 2-3, 4-1).
In the process of isothermal expansion 1-2, the entropy of the working fluid ... 2) does not change
2. 183. A change in the internal energy of a gas during an isochoric process is possible ... 2) without heat exchange with the external environment
3. 184. When the gun was fired, the projectile flew out of the barrel, located at an angle to the horizon, rotating around its longitudinal axis with an angular velocity . The moment of inertia of the projectile about this axis, the time of movement of the projectile in the barrel. A moment of force acts on the barrel of a gun during a shot ... 1)
Rotor of an electric motor rotating at a speed 
, after turning off, it stopped after 10s. The angular acceleration of the rotor deceleration after turning off the electric motor remained constant. The dependence of the speed on the braking time is shown in the graph. The number of revolutions that the rotor made before stopping is ... 3) 80
5. 186. An ideal gas has the minimum internal energy in the state...
2) 1
6. 187. A ball of radius R and mass M rotates with an angular velocity . The work required to increase the speed of its rotation by 2 times is equal to ... 4)
7. 189 . After a time interval equal to two half-lives, undecayed radioactive atoms will remain ... 2)25%
8. 206 . A heat engine operating according to the Carnot cycle (see figure) performs work equal to ...
4)
9. 207. If for polyatomic gas molecules at temperatures the contribution of the energy of nuclear vibrations to the heat capacity of the gas is negligible, then of the ideal gases proposed below (hydrogen, nitrogen, helium, water vapor), the isochoric heat capacity (universal gas constant) has one mole ... 2) water vapor
10. 208.
An ideal gas is transferred from state 1 to state 3 in two ways: along the path 1-3 and 1-2-3. The ratio of work done by the gas is... 3) 1,5
11. 210. With a 3-fold increase in pressure and a 2-fold decrease in volume, the internal energy of an ideal gas ... 3) will increase by 1.5 times
12. 211.
13. A ball with a radius rolls evenly without slipping along two parallel rulers, the distance between which , and passes 120cm in 2s. The angular velocity of the ball is... 2)
14. 212 . A cord is wound on the drum with a radius, to the end of which a load of mass is attached. The load descends with acceleration. The moment of inertia of the drum... 3)
15. 216. A rectangular wire frame is located in the same plane with a straight long conductor, through which current I flows. The induction current in the frame will be directed clockwise when it ...
3) translational movement in the negative direction of the OX axis
16. 218. A frame with a current with a magnetic dipole moment, the direction of which is indicated in the figure, is in a uniform magnetic field:
The moment of forces acting on a magnetic dipole is directed ... 2) perpendicular to the plane of the picture to us
17. 219. The average kinetic energy of gas molecules at temperature depends on their configuration and structure, which is associated with the possibility of various types of movement of atoms in a molecule and the molecule itself. Provided that there is a translational and rotational motion of the molecule as a whole, the average kinetic energy of a water vapor molecule () is ... 3)
18. 220. The eigenfunctions of an electron in a hydrogen atom contain three integer parameters: n, l, and m. The parameter n is called the main quantum number, the parameters l and m are called the orbital (azimuthal) and magnetic quantum numbers, respectively. The magnetic quantum number m determines ... 1) the projection of the orbital angular momentum of the electron on a certain direction
19. 221.
Stationary Schrödinger equation 
describes the motion of a free particle if the potential energy has the form ... 2)
20. 222. The figure shows graphs that reflect the nature of the dependence of the polarization P of the dielectric on the strength of the external electric field E.
Nonpolar dielectrics correspond to the curve ... 1) 4
21. 224. A horizontally flying bullet pierces a block lying on a smooth horizontal surface. In the "bullet - bar" system ... 1) momentum is conserved, mechanical energy is not conserved
22. The hoop rolls down a hill 2.5 m high without slipping. The speed of the hoop (in m/s) at the base of the hill, provided that friction can be neglected, is equal to ... 4) 5
23. 227. T The momentum of the body changed under the action of a short-term impact and became equal, as shown in the figure:
At the moment of impact, the force acted in the direction of ... Answer: 2
24. 228. The accelerator told the radioactive nucleus the speed (c is the speed of light in vacuum). At the moment of departure from the accelerator, the nucleus ejected a β-particle in the direction of its movement, the speed of which is relative to the accelerator. The speed of the β-particle relative to the nucleus is … 1) 0.5 s
25. 231. The average kinetic energy of gas molecules at temperature depends on their configuration and structure, which is associated with the possibility of various types of movement of atoms in a molecule and the molecule itself. Provided that there is a translational, rotational motion of the molecule as a whole and an oscillatory motion of atoms in the molecule, the ratio of the average kinetic energy of the oscillatory motion to the total kinetic energy of the nitrogen molecule () is ... 3) 2/7
26. 232. The spin quantum number s determines ... intrinsic mechanical moment of an electron in an atom
27. 233. If a hydrogen molecule, a positron, a proton and a -particle have the same de Broglie wavelength, then ... 4) positron
28. The particle is in a rectangular one-dimensional potential box with impenetrable walls 0.2 nm wide. If the energy of a particle at the second energy level is 37.8 eV, then at the fourth energy level it is _____ eV. 2) 151,2
29. The stationary Schrödinger equation in the general case has the form 
. Here 
potential energy of a microparticle. An electron in a one-dimensional potential box with infinitely high walls corresponds to the equation ... 1) 
30. The complete system of Maxwell's equations for the electromagnetic field in integral form has the form:
,
,
The following system of equations:
valid for... 4) electromagnetic field in the absence of free charges
31. The figure shows the sections of two straight long parallel conductors with oppositely directed currents, and. The magnetic field induction is equal to zero in the section ...
4) d
32. A conductive jumper moves along parallel metal conductors located in a uniform magnetic field with constant acceleration (see Fig.). If the resistance of the jumper and guides can be neglected, then the dependence of the induction current on time can be represented by a graph ...
33. The figures show the time dependence of the speed and acceleration of a material point oscillating according to the harmonic law.
The cyclic oscillation frequency of the point is ______ Answer: 2
34. Two harmonic oscillations of the same direction with the same frequencies and amplitudes equal to and are added. Establish a correspondence between the phase difference of the added oscillations and the amplitude of the resulting oscillation.
35. Answer options:
36. If the frequency of an elastic wave is increased by 2 times without changing its speed, then the intensity of the wave will increase by ___ times (s). Answer: 8
37. The equation of a plane wave propagating along the OX axis has the form 
. The wavelength (in m) is ... 4) 3,14
38. A photon with an energy of 100 keV as a result of Compton scattering on an electron was deflected by an angle of 90 °. The energy of the scattered photon is _____. Express your answer in keV and round to the nearest whole number. Note that the rest energy of an electron is 511 keV Answer: 84
39. The angle of refraction of a beam in a liquid is If it is known that the reflected beam is completely polarized, then the refractive index of the liquid is ... 3) 1,73
40. If the axis of rotation of a thin-walled circular cylinder is transferred from the center of mass to the generatrix (Fig.), Then the moment of inertia about the new axis is _____ times.
1) will increase by 2
41. A disk rolls uniformly on a horizontal surface at a speed without slipping. The velocity vector of point A, lying on the rim of the disk, is oriented in the direction ...
3) 2
42. A small puck begins to move without initial speed along a smooth ice hill from point A. Air resistance is negligible. The dependence of the potential energy of the puck on the x coordinate is shown in the graph:
The kinetic energy of the puck at point C is ______ than at point B. 4) 2 times more
43. Two small massive balls are fixed at the ends of a weightless rod of length l. The rod can rotate in a horizontal plane around a vertical axis passing through the middle of the rod. The rod is spun up to an angular velocity of . Under the action of friction, the rod stopped, and 4 J of heat were released.
44. If the rod is untwisted to an angular velocity, then when the rod stops, an amount of heat (in J) will be released equal to ... Answer : 1
45. Light waves in a vacuum are ... 3) transverse
46. The figures show the time dependence of the coordinates and speed of a material point oscillating according to the harmonic law:
47. The cyclic oscillation frequency of a point (in) is equal to ... Answer: 2
48. The density of the energy flux carried by a wave in an elastic medium with density increased 16 times at a constant wave speed and frequency. At the same time, the amplitude of the wave increased by _____ times (a). Answer: 4
49. The magnitude of the saturation photocurrent with an external photoelectric effect depends ... 4) on the intensity of the incident light
50. The figure shows a diagram of the energy levels of the hydrogen atom, and also conditionally depicts the transitions of an electron from one level to another, accompanied by the emission of an energy quantum. In the ultraviolet region of the spectrum, these transitions give the Lyman series, in the visible region, the Balmer series, in the infrared region, the Paschen series, and so on.
The ratio of the minimum line frequency in the Balmer series to the maximum line frequency in the Lyman series of the spectrum of the hydrogen atom is ... 3)5/36
51. The ratio of the de Broglie wavelengths of a neutron and an α-particle having the same speed is ... 4) 2
52. The stationary Schrödinger equation has the form 
. This equation describes... 2) linear harmonic oscillator
53. The figure schematically shows the Carnot cycle in coordinates:
54. 
55. An increase in entropy takes place in the area ... 1) 1–2
56. The dependences of the pressure of an ideal gas in an external uniform gravity field on height for two different temperatures are shown in the figure.
57. For the graphs of these functions, the statements are incorrect that ... 3) the dependence of the pressure of an ideal gas on height is determined not only by the temperature of the gas, but also by the mass of the molecules 4) temperature below temperature
1.
The stationary Schrödinger equation has the form 
.
This equation describes... an electron in a hydrogen-like atom
The figure schematically shows the Carnot cycle in coordinates: 
The increase in entropy takes place in the region 1–2
2. On ( P,V)-diagram shows 2 cyclic processes. 
The ratio of work done in these cycles is ... Answer: 2.
3. Dependences of ideal gas pressure in an external uniform gravity field on height for two different temperatures are shown in the figure. 
For the graphs of these functions unfaithful are statements that ... the temperature is lower than the temperature
the dependence of the pressure of an ideal gas on height is determined not only by the temperature of the gas, but also by the mass of the molecules
4. At room temperature, the ratio of molar heat capacities at constant pressure and constant volume is 5/3 for ... helium
5. The figure shows the trajectories of charged particles flying at the same speed into a uniform magnetic field perpendicular to the plane of the figure. At the same time, for the charges and specific charges of particles, the statement is true ... 
, , 
6. unfaithful for ferromagnets is the statement ...
The magnetic permeability of a ferromagnet is a constant value that characterizes its magnetic properties.
7. Maxwell's equations are the basic laws of classical macroscopic electrodynamics, formulated on the basis of a generalization of the most important laws of electrostatics and electromagnetism. These equations in integral form have the form:
1). 
;
2). 
;
3). 
;
4). 0.
Maxwell's fourth equation is a generalization of...
the Ostrogradsky–Gauss theorem for a magnetic field
8. A bird sits on a power line wire, the resistance of which is 2.5 10 -5 Ohm for every meter of length. If a current flowing through the wire is 2 kA, and the distance between the legs of the bird is 5 cm, then the bird is energized ...
9. Current strength in a conducting circular circuit with an inductance of 100 mH changes over time
by law (in SI units): 
The absolute value of the EMF of self-induction at time 2 With equals ____ ; while the induced current is directed ...
0,12 IN; counterclock-wise
10. An electrostatic field is created by a system of point charges. 
The field strength vector at point A is oriented in the direction ...
11. The angular momentum of an electron in an atom and its spatial orientations can be conditionally depicted by a vector diagram, on which the length of the vector is proportional to the modulus of the orbital angular momentum of the electron. The figure shows the possible orientations of the vector . 
The minimum value of the principal quantum number n for the specified state is 3
12. The stationary Schrödinger equation in the general case has the form 
. Here 
potential energy of a microparticle. The motion of a particle in a three-dimensional infinitely deep potential box describes the equation 
13. The figure schematically shows the stationary orbits of an electron in a hydrogen atom according to the Bohr model, and also shows the transitions of an electron from one stationary orbit to another, accompanied by the emission of an energy quantum. In the ultraviolet region of the spectrum, these transitions give the Lyman series, in the visible - the Balmer series, in the infrared - the Paschen series. 
The highest quantum frequency in the Paschen series (for the transitions shown in the figure) corresponds to the transition 
14. If the proton and deuteron have passed the same accelerating potential difference, then the ratio of their de Broglie wavelengths is
15. The figure shows the velocity vector of a moving electron: 
The vector of magnetic induction of the field created by the electron when moving, at a point WITH sent ... from us
16. A small electric kettle can boil a glass of water for tea or coffee in the car. Battery voltage 12 IN. If he is 5 min heats 200 ml water from 10 to 100° WITH, then the current strength (in A) consumed from the battery is equal to ...
(The heat capacity of water is 4200 j/kg. TO.) 21
17. Conductive flat circuit with an area of 100 cm 2 located in a magnetic field perpendicular to the lines of magnetic induction. If the magnetic induction changes according to the law 
Tl, then the induction emf that occurs in the circuit at the moment of time (at mV), is equal to 0.1
18. The orientational polarization of dielectrics is characterized by the influence of the thermal motion of molecules on the degree of polarization of the dielectric
19. The figures show graphs of the field strength for various charge distributions: 
Plot for a charged metal sphere of radius R shown in the figure ... Answer: 2.
20. Maxwell's equations are the basic laws of classical macroscopic electrodynamics, formulated on the basis of a generalization of the most important laws of electrostatics and electromagnetism. These equations in integral form have the form:
1). 
;
2). 
;
3). 
;
4). 0.
The third Maxwell equation is a generalization of the Ostrogradsky–Gauss theorem for an electrostatic field in a medium
21. The dispersion curve in the region of one of the absorption bands has the form shown in the figure. Relationship between phase and group velocities for section bc looks like... 
22. Sunlight falls on a mirror surface along the normal to it. If the intensity of solar radiation is 1.37 kW/m 2, then the pressure of light on the surface is _____ . (Express your answer in µPa and round up to a whole number). Answer: 9.
23. The phenomenon of external photoelectric effect is observed. In this case, with a decrease in the wavelength of the incident light, the value of the retarding potential difference increases
24. A plane light wave with a wavelength falls on a diffraction grating along the normal to its surface. If the grating constant is , then the total number of main maxima observed in the focal plane of the converging lens is ... Answer: 9.
25. A particle moves in a two-dimensional field, and its potential energy is given by the function . The work of the field forces to move the particle (in J) from point C (1, 1, 1) to point B (2, 2, 2) is ...
(The function and coordinates of the points are given in SI units.) Answer: 6.
26. The skater rotates around a vertical axis with a certain frequency. If he presses his hands to his chest, thereby reducing his moment of inertia relative to the axis of rotation by 2 times, then the figure skater's rotation frequency and his kinetic energy of rotation will increase by 2 times
27. An emblem in the form of a geometric figure is applied on board the spacecraft:
If the ship moves in the direction indicated by the arrow in the figure, with a speed comparable to the speed of light, then in a fixed frame of reference the emblem will take the form shown in the figure
28. Three bodies are considered: a disk, a thin-walled pipe and a ring; and the masses m and radii R their bases are the same. 
For the moments of inertia of the bodies under consideration relative to the specified axes, the following relation is true: 
29. The disk rotates uniformly around a vertical axis in the direction indicated by the white arrow in the figure. At some point in time, a tangential force was applied to the disk rim. 
In this case, the vector 4 correctly depicts the direction of the angular acceleration of the disk
30. The figure shows a graph of the dependence of the speed of the body on time t. 
If body weight is 2 kg, then the force (in H) acting on the body is equal to ... Answer: 1.
31. Establish a correspondence between the types of fundamental interactions and radii (in m) their actions.
1.Gravity
2. Weak
3. Strong
32. -decay is a nuclear transformation occurring according to the scheme 
33. Charge in units of electron charge is +1; the mass in units of electron mass is 1836.2; spin in units is 1/2. These are the main characteristics of the proton
34. The law of conservation of lepton charge prohibits the process described by the equation 
35. In accordance with the law of uniform distribution of energy over degrees of freedom, the average kinetic energy of an ideal gas molecule at a temperature T is equal to: . Here , where , and are the degrees of freedom of the translational, rotational, and vibrational motions of the molecule, respectively. For hydrogen () number i equals 7
36. A diagram of the cyclic process of an ideal monatomic gas is shown in the figure. The ratio of work during heating to the work of gas for the entire cycle modulo is ...
37. The figure shows graphs of the distribution functions of ideal gas molecules in an external uniform gravity field versus height for two different gases, where are the masses of gas molecules (Boltzmann distribution). 
For these functions, the statements are true that ...
mass is more than mass
the concentration of gas molecules with less mass at the "zero level" is less
38. When heat enters a non-isolated thermodynamic system in the course of a reversible process, for the entropy increment, the following relation will be correct:
39. The traveling wave equation has the form: , where expressed in millimeters, - in seconds, - in meters. The ratio of the amplitude value of the speed of particles of the medium to the speed of wave propagation is 0.028
40. The amplitude of damped oscillations decreased by a factor of ( is the base of the natural logarithm) for . The attenuation coefficient (in) is ... Answer: 20.
41. Two harmonic oscillations of the same direction are added with the same frequencies and equal amplitudes. Establish a correspondence between the amplitude of the resulting oscillation and the phase difference of the added oscillations.
1. 2. 3. Answer: 2 3 1 0
42. The figure shows the orientation of the electric () and magnetic () field strength vectors in an electromagnetic wave. The energy flux density vector of the electromagnetic field is oriented in the direction of … 
43. Two conductors are charged to potentials 34 IN and -16 IN. Charge 100 nCl must be transferred from the second conductor to the first. In this case, work must be done (in µJ) equal to ... Answer: 5.
44. The figure shows bodies of the same mass and size, rotating around a vertical axis with the same frequency. Kinetic energy of the first body J. If kg, cm, then the angular momentum (in mJ s) of the second body is equal to ... 
The main task of the theories of chemical kinetics is to offer a method for calculating the rate constant of an elementary reaction and its dependence on temperature, using different ideas about the structure of the reactants and the reaction path. We will consider two simplest theories of kinetics - the theory of active collisions (TAS) and the theory of activated complex (TAK).
Theory of active collisions is based on counting the number of collisions between reacting particles, which are represented as hard spheres. It is assumed that the collision will lead to a reaction if two conditions are met: 1) the translational energy of the particles exceeds the activation energy E A; 2) the particles are correctly oriented in space relative to each other. The first condition introduces the factor exp(- E A/RT), which is equal to percentage of active collisions in the total number of collisions. The second condition gives the so-called steric factor P- a constant characteristic of this reaction.
The TAS has obtained two basic expressions for the rate constant of a bimolecular reaction. For a reaction between different molecules (A + B products), the rate constant is
Here N A is the Avogadro constant, r are the radii of the molecules, M- molar masses of substances. The factor in large parentheses is the average speed of the relative motion of particles A and B.
The rate constant of a bimolecular reaction between identical molecules (2A products) is:
(9.2)
From (9.1) and (9.2) it follows that the temperature dependence of the rate constant has the form:
.
According to TAS, the pre-exponential factor depends only slightly on temperature. Experienced activation energy E op, determined by equation (4.4), is related to the Arrhenius, or true activation energy E A ratio:
E op = E A - RT/2.
Monomolecular reactions within TAS are described using the Lindemann scheme (see Problem 6.4), in which the activation rate constant k 1 is calculated by formulas (9.1) and (9.2).
IN activated complex theory an elementary reaction is represented as a monomolecular decomposition of an activated complex according to the scheme:
It is assumed that there is a quasi-equilibrium between the reactants and the activated complex. The rate constant of monomolecular decomposition is calculated by the methods of statistical thermodynamics, representing the decomposition as a one-dimensional translational motion of the complex along the reaction coordinate.
The basic equation of the activated complex theory is:
, (9.3)
Where k B= 1.38 . 10 -23 J/K - Boltzmann's constant, h= 6.63 . 10 -34 J. s - Planck's constant, - equilibrium constant for the formation of an activated complex, expressed in terms of molar concentrations (in mol / l). Depending on how the equilibrium constant is estimated, there are statistical and thermodynamic aspects of SO.
IN statistical approach, the equilibrium constant is expressed in terms of sums over states:
, (9.4)
where is the total sum over the states of the activated complex, Q react is the product of the total sums over the states of the reactants, is the activation energy at absolute zero, T = 0.
The total sums over states are usually decomposed into factors corresponding to certain types of molecular motion: translational, electronic, rotational and vibrational:
Q = Q fast. Q email . Q temp. . Q count
Translational sum over states for a particle of mass m is equal to:
Q post = .
This translational amount has the dimension (volume) -1, because through it the concentrations of substances are expressed.
The electronic sum over states at ordinary temperatures is, as a rule, constant and equal to the degeneracy of the ground electronic state: Q email = g 0 .
The rotational sum over states for a diatomic molecule is:
Q vr = ,
where m = m 1 m 2 / (m 1 +m 2) is the reduced mass of the molecule, r- internuclear distance, s = 1 for asymmetric molecules AB and s =2 for symmetrical molecules A 2 . For linear polyatomic molecules, the rotational sum over states is proportional to T, and for nonlinear molecules - T 3/2. At ordinary temperatures, rotational sums over states are of the order of 10 1 -10 2 .
The vibrational sum over the states of a molecule is written as a product of factors, each of which corresponds to a certain vibration:
Q count = 
,
Where n- number of vibrations (for a linear molecule consisting of N atoms, n = 3N-5, for non-linear molecule n = 3N-6), c= 3 . 10 10 cm/s - speed of light, n i- oscillation frequencies, expressed in cm -1 . At ordinary temperatures, the vibrational sums over states are very close to 1 and noticeably differ from it only under the condition: T>n. At very high temperatures, the vibrational sum for each vibration is directly proportional to the temperature:
Q i 
.
The difference between an activated complex and ordinary molecules is that it has one less vibrational degree of freedom, namely: the vibration that leads to the decomposition of the complex is not taken into account in the vibrational sum over states.
IN thermodynamic approach, the equilibrium constant is expressed in terms of the difference between the thermodynamic functions of the activated complex and the initial substances. For this, the equilibrium constant expressed in terms of concentrations is converted into a constant expressed in terms of pressures. The last constant is known to be related to the change in the Gibbs energy in the reaction of the formation of an activated complex:
.
For a monomolecular reaction in which the formation of an activated complex occurs without changing the number of particles, = and the rate constant is expressed as follows:
Entropy factor exp ( S /R) is sometimes interpreted as a steric factor P from the theory of active collisions.
For a bimolecular reaction occurring in the gas phase, a factor is added to this formula RT / P 0 (where P 0 \u003d 1 atm \u003d 101.3 kPa), which is needed to go from to:
For a bimolecular reaction in solution, the equilibrium constant is expressed in terms of the Helmholtz energy of formation of the activated complex:
Example 9-1. Bimolecular reaction rate constant
2NO2 2NO + O2
at 627 K is 1.81. 10 3 cm 3 / (mol. s). Calculate the true activation energy and the proportion of active molecules, if the diameter of the NO 2 molecule can be taken equal to 3.55 A, and the steric factor for this reaction is 0.019.
Solution. In the calculation, we will rely on the theory of active collisions (formula (9.2)):
.
This number represents the proportion of active molecules.
When calculating the rate constants using various theories of chemical kinetics, one must be very careful with the dimensions. Note that the radius of the molecule and the average speed are expressed in cm to give a constant in cm 3 /(mol. s). The factor 100 is used to convert m/s to cm/s.
The true activation energy can be easily calculated in terms of the fraction of active molecules:
J/mol = 166.3 kJ/mol.
Example 9-2. Using the activated complex theory, determine the temperature dependence of the rate constant of the trimolecular reaction 2NO + Cl 2 = 2NOCl at temperatures close to room temperature. Find the connection between experienced and true activation energies.
Solution. According to the statistical variant SO, the rate constant is (formula (9.4)):
.
In the sums over the states of the activated complex and reagents, we will not take into account the vibrational and electronic degrees of freedom, since at low temperatures, the vibrational sums over states are close to unity, while the electronic sums are constant.
The temperature dependences of the sums over the states, taking into account the translational and rotational motions, have the form:
The activated complex (NO) 2 Cl 2 is a nonlinear molecule, therefore its rotational sum over states is proportional to T 3/2 .
Substituting these dependencies into the expression for the rate constant, we find:
We see that trimolecular reactions are characterized by a rather unusual dependence of the rate constant on temperature. Under certain conditions, the rate constant can even decrease with increasing temperature due to the pre-exponential factor!
The experimental activation energy of this reaction is:
.
Example 9-3. Using the statistical version of the activated complex theory, obtain an expression for the rate constant of a monomolecular reaction.
Solution. For a monomolecular reaction
A AN products
the rate constant, according to (9.4), has the form:
.
An activated complex in a monomolecular reaction is an excited reactant molecule. The translational sums of the reagent A and the complex AN are the same (the mass is the same). If we assume that the reaction occurs without electronic excitation, then the electronic sums over states are the same. If we assume that the structure of the reactant molecule does not change very much upon excitation, then the rotational and vibrational sums over the states of the reactant and the complex are almost the same, with one exception: the activated complex has one less vibration than the reactant. Consequently, the vibration leading to bond cleavage is taken into account in the sum over the states of the reactant and is not taken into account in the sum over the states of the activated complex.
Carrying out the reduction of the same sums by states, we find the rate constant of a monomolecular reaction:
where n is the frequency of the oscillation that leads to the reaction. speed of light c is the multiplier that is used if the oscillation frequency is expressed in cm -1 . At low temperatures, the vibrational sum over the states is equal to 1:
.
At high temperatures, the exponential in the vibrational sum over states can be expanded into a series: exp(- x) ~ 1 - x:
.
This case corresponds to a situation where, at high temperatures, each oscillation leads to a reaction.
Example 9-4. Determine the temperature dependence of the rate constant for the reaction of molecular hydrogen with atomic oxygen:
H2+O. HO. +H. (linear activated complex)
at low and high temperatures.
Solution. According to the activated complex theory, the rate constant for this reaction is:
We assume that the electron factors do not depend on temperature. All translational sums over states are proportional T 3/2 , rotational sums over states for linear molecules are proportional to T, the vibrational sums over states at low temperatures are equal to 1, and at high temperatures they are proportional to the temperature to a degree equal to the number of vibrational degrees of freedom (3 N- 5 = 1 for H molecule 2 and 3 N- 6 = 3 for a linear activated complex). Considering all this, we find that at low temperatures
and at high temperatures
Example 9-5. The acid-base reaction in a buffer solution proceeds according to the mechanism: A - + H + P. The dependence of the rate constant on temperature is given by the expression
k = 2.05 . 10 13.e-8681/ T(l. mol -1. s -1).
Find the experimental activation energy and activation entropy at 30 o C.
Solution. Since the bimolecular reaction occurs in solution, we use expression (9.7) to calculate the thermodynamic functions. It is necessary to introduce the experimental activation energy into this expression. Since the pre-exponential factor in (9.7) depends linearly on T, That E op = + RT. Replacing in (9.7) by E oops, we get:
.
It follows that the experimental activation energy is equal to E op = 8681. R= 72140 J/mol. The activation entropy can be found from the pre-exponential factor:
,
whence = 1.49 J/(mol. K).
9-1. The diameter of the methyl radical is 3.8 A. What is the maximum rate constant (in l / (mol. s)) of the recombination of methyl radicals at 27 o C? (answer)
9-2. Calculate the value of the steric factor in the ethylene dimerization reaction
2C2H4C4H8
at 300 K, if the experimental activation energy is 146.4 kJ/mol, the effective diameter of ethylene is 0.49 nm, and the experimental rate constant at this temperature is 1.08. 10 -14 cm 3 / (mol. s).
9-7. Determine the temperature dependence of the rate constant for the reaction H . + Br 2 HBr + Br. (nonlinear activated complex) at low and high temperatures. (Answer)
9-8. For the reaction CO + O 2 = CO 2 + O, the dependence of the rate constant on temperature at low temperatures has the form:
k( T) ~ T-3/2. exp(- E 0 /RT)
(answer)
9-9. For the reaction 2NO = (NO) 2, the dependence of the rate constant on temperature at low temperatures has the form:
k( T) ~ T-1exp(- E 0/R T)
What configuration - linear or nonlinear - does the activated complex have? (Answer)
9-10. Using the active complex theory, calculate the true activation energy E 0 for reaction
CH3. + C 2 H 6 CH 4 + C 2 H 5.
at T\u003d 300 K if the experimental activation energy at this temperature is 8.3 kcal / mol. (Answer)
9-11. Derive the ratio between the experimental and true activation energies for the reaction
9-12. Determine the activation energy of a monomolecular reaction at 1000 K if the frequency of vibrations along the broken bond is n = 2.4. 10 13 s -1 , and the rate constant is k\u003d 510 min -1. (answer)
9-13. The rate constant of the reaction of the first order of decomposition of bromoethane at 500 o C is 7.3. 10 10 s -1 . Estimate the activation entropy of this reaction if the activation energy is 55 kJ/mol. (answer)
9-14. Decomposition of di-peroxide tert-butyl in the gas phase is a first order reaction whose rate constant (in s -1) depends on temperature as follows:
Using the theory of the activated complex, calculate the enthalpy and entropy of activation at a temperature of 200 o C. (answer)
9-15. The isomerization of diisopropyl ether to allylacetone in the gas phase is a first order reaction whose rate constant (in s -1) depends on temperature as follows:
Using the theory of the activated complex, calculate the enthalpy and entropy of activation at a temperature of 400 o C. (answer)
9-16. The dependence of the rate constant of decomposition of vinyl ethyl ether
C 2 H 5 -O-CH \u003d CH 2 C 2 H 4 + CH 3 CHO
temperature has the form
k = 2.7. 10 11.e -10200/ T(with -1).
Calculate the entropy of activation at 530 o C. (answer)
9-17. In the gas phase, substance A unimolecularly transforms into substance B. The rate constants of the reaction at temperatures of 120 and 140 o C are, respectively, 1.806. 10 -4 and 9.14. 10 -4 s -1 . Calculate the average entropy and heat of activation in this temperature range.
If we do not take into account the vibrational motions in the carbon dioxide molecule, then the average kinetic energy of the molecule is equal to ...
Solution: The average kinetic energy of a molecule is: , where is the Boltzmann constant, is the thermodynamic temperature; - the sum of the number of translational, rotational and twice the number of vibrational degrees of freedom of the molecule: . For a carbon dioxide molecule, the number of degrees of freedom of translational motion, rotational - , vibrational - , therefore, therefore, the average kinetic energy of the molecule is: .
TASK N 2 Topic: The first law of thermodynamics. Working with isoprocesses
The figure shows a diagram of the cyclic process of an ideal monatomic gas: 
During the cycle, the gas receives an amount of heat (in) equal to ...
Solution: The cycle consists of isochoric heating (4–1), isobaric expansion (1–2), isochoric cooling (2–3), and isobaric compression (3–4). In the first two stages of the cycle, the gas receives heat. According to the first law of thermodynamics, the amount of heat received by a gas is 
, where is the change in internal energy, is the work of the gas. Then . Thus, the amount of heat received by the gas per cycle is
TASK N 3 Topic: The second law of thermodynamics. Entropy
In the course of an irreversible process, when heat enters a non-isolated thermodynamic system, for the increment of entropy, the following relation will be correct: ...
Solution: The ratio in a reversible process is the total differential of the system state function, called the entropy of the system: 
. In isolated systems, entropy cannot decrease with any processes occurring in it: . The equal sign refers to reversible processes, and the greater than sign refers to irreversible processes. If heat enters a non-isolated system and an irreversible process occurs, then the entropy increases due not only to the received heat, but also to the irreversibility of the process: .
Task n 4 Topic: Maxwell and Boltzmann distributions
The figure shows a graph of the velocity distribution function of ideal gas molecules (Maxwell distribution), where 
is the fraction of molecules whose velocities are in the range of velocities from to per unit of this interval: 
For this function, the statements are true ...
|
the position of the maximum of the curve depends not only on the temperature, but also on the nature of the gas (its molar mass) |
|||
|
as the number of molecules increases, the area under the curve does not change |
|||
|
with increasing gas temperature, the value of the maximum of the function increases |
|||
|
for a gas with a higher molar mass (at the same temperature), the maximum of the function is located in the region of higher velocities |
Solution: It follows from the definition of the Maxwell distribution function that the expression 
determines the proportion of molecules whose velocities are in the range of velocities from to (on the graph, this is the area of the shaded strip). Then the area under the curve is 
and does not change with changes in temperature and the number of gas molecules. From the most probable speed formula 
(at which the function is maximum) it follows that is directly proportional and inversely proportional to , where and are the temperature and molar mass of the gas, respectively.
TASK N 5 Topic: Electrostatic field in vacuum
The figures show graphs of the field strength for various charge distributions: 
Dependency plot for a sphere of radius R, uniformly charged in volume, is shown in the figure ...
TASK N 6 Topic: Direct Current Laws
The figure shows the dependence of the current density j flowing in conductors 1 and 2, on the strength of the electric field E:
The ratio of specific resistances r 1 / r 2 of these conductors is ...
TASK N 7 Topic: Magnetostatics
A frame with a current with a magnetic dipole moment, the direction of which is indicated in the figure, is in a uniform magnetic field: 
The moment of forces acting on a magnetic dipole is directed ...
|
perpendicular to the plane of the picture to us |
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|
perpendicular to the plane of the picture from us |
|||
|
in the direction of the magnetic induction vector |
|||
|
opposite to the magnetic induction vector |
MINISTRY OF EDUCATION AND SCIENCE OF THE REPUBLIC OF TATARSTAN
ALMETYEVSK STATE OIL INSTITUTE
Department of Physics
on the topic of: "Debye's Law of Cubes"
Completed by a student of group 18-13B Gontar I.V. Instructor: Mukhetdinova Z.Z.
Almetyevsk 2010
1. The energy of the crystal lattice ……………………………… 3
2. Einstein model …………………………………………….. 6
3. Debye model ………………………………………………….. 7
4. The law of Debye cubes ………………………………………………… 8
5. Debye’s Achievements……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………….
6. References …………………………………………….. 12
Crystal lattice energy
A feature of a solid body is the presence of long-range and short-range orders. In an ideal crystal, the particles occupy certain positions and it is not necessary to take into account N! in statistical calculations.
The energy of the crystal lattice of a monatomic crystal consists of two main contributions: E = U o + E kol. Atoms vibrate in a lattice. For polyatomic particles forming a crystal, it is necessary to take into account the internal degrees of freedom: vibrations and rotations. If we do not take into account the anharmonicity of atomic vibrations, which gives the dependence of U o on temperature (change in the equilibrium positions of atoms), U o can be equated to the potential energy of the crystal and does not depend on T. At T = 0, the energy of the crystal lattice, i.e. the energy for removing crystal particles to an infinite distance will be equal to E cr = - E o = - (U o + E o, count).
Here E o, count is the energy of zero oscillations. Usually this value is of the order of 10 kJ/mol and much less than U o. Consider Ecr = - Uo. (The method of the largest summand). Ecr in ionic and molecular crystals up to 1000 kJ / mol, in molecular and in crystals with hydrogen bonds: up to 20 kJ / mol (CP 4 - 10, H 2 O - 50). The values are determined from experience or calculated on the basis of some model: ionic interaction according to the pendant, van der Waals forces according to the Sutherland potential.
Consider an ionic crystal of NaCl having a face-centered cubic lattice: in the lattice each ion has 6 neighbors of the opposite sign at a distance R, in the next second layer 12 neighbors of the same sign at a distance of 2 1/2 R, the 3rd layer: 8 ions at a distance of 3 1/2 R, 4th layer: 6 ions at 2R, etc.
The potential energy of a crystal of 2N ions will be U = Nu, where u is the energy of the interaction of the ion with its neighbors. The interaction energy of ions consists of two terms: short-range repulsion due to valence forces (1st term) and attraction or repulsion of charges: 
+ sign for repulsion of the same, - attraction of different ions. e - charge. We introduce the value of the reduced distance p ij = r ij / R, where r ij is the distance between the ions, R is the lattice parameter.
The energy of interaction of an ion with all neighbors where
Madelung's constant \u003d 6/1 - 12/2 1/2 + 8/3 1/2 - 6/2 + .... Here - for ions of the same charge sign, + for different ones. For NaCl a = 1.747558... A n = S 1/ p ij n in the first term. The distance R o (half of the edge of the cube in this case) corresponds to the minimum potential energy at T = 0 and can be determined from crystallography data and knowing the repulsion potential. It's obvious that 
and then
From here we find A n and the energy 
or 
.
n is the parameter of the repulsion potential and is usually ³ 10, i.e. the main contribution is made by the Coulomb interaction (we assume that R does not noticeably depend on T), and the repulsion is less than 10%.
For NaCl, the Coulomb interaction is 862, the repulsion is 96 kJ/mol (n = 9). For molecular crystals, it can be calculated by potential 6-12 and the energy will be equal to 
z 1 is the number of atoms in the 1st coordination sphere, R 1 is the radius of the first coordination sphere, b is the potential parameter.
For non-ionic crystals, the vibrational component of the energy must be taken into account. There are no translational and rotational movements at absolute zero. What remains is the vibrational component of the energy. Vibrations 3N - 6, but translational and rotational vibrations refer to the crystal as a whole. Roughly, we can assume 3N, because N (large, the number of particles in the crystal). Then all 3N degrees of freedom of a crystal of N particles are oscillatory. In principle, it is easy to calculate the sum over states and thermodynamic functions. But you need to know the frequency spectrum of crystal vibrations. The point is that the displacement of a particle causes the displacement of others and the oscillators are coupled. The total sum over the states of oscillatory motion will be determined:
.
Because is a crystal, then on N ! no need to share. The average energy is equal to the derivative of lnZ with respect to T at constant V, multiplied by kT 2 . Hence, the lattice energy is equal to the sum of the contributions of the potential and vibrational energies, 
and the entropy S = E/ T + k ln(Z).
Two main models are used for the calculation.
Einstein Model
All frequencies are considered the same: a set of one-dimensional harmonic oscillators. The sum over the states of the three-dimensional oscillator consists of 3 identical terms q = [ 2sh(hn/ 2kT)] -3 . For N particles there will be 3N factors. Those. energy 
At high T, expanding the exponential into a series, the limit sh(hn/ 2kT) = hn/ 2kT and 
Entropy of oscillatory motion 
Heat capacity of crystals: 
The OP has a mistake. Hence, at large T >> q E = hn/ k, the limit C v ® 3Nk: The Dulong-Petit law for monatomic crystals. AND 
(The exponent quickly tends to 0).
In the classical approximation, Ecol without zero oscillations is equal to 3NkT and the contribution of oscillations to the heat capacity is 3Nk = 3R. Calculation according to Einstein: the lower curve, which deviates more noticeably from the experimental data.
Einstein's model gives the equation of state for a solid body: (according to Melvin-Hughes)
u o = - q sublimation, m, n - experimental parameters, so for xenon m = 6, n = 11, a o - interatomic distance at T = 0. Ie. pV/ RT = f(n, a o , n, m).
But near T = 0, Einstein's assumption of identical frequencies does not work. Oscillators can differ in the strength of interaction and frequency. Experience at low temperatures shows a cubic dependence on temperature.
Debye model
Debye proposed a model for the existence of a continuous spectrum of frequencies (strictly for low frequencies, for thermal vibrations - phonons) up to a certain maximum. The frequency distribution function of harmonic oscillators has the form , where c l, c t- velocity of propagation of longitudinal and transverse vibration waves. At frequencies above the maximum g = 0.
The areas under the two curves must be the same. In reality, there is a certain spectrum of frequencies, the crystal is not isotropic (usually this is neglected and the velocities of wave propagation in directions are assumed to be the same). It may be that the maximum Debye frequency is higher than the real ones, which follows from the condition of equal areas. The value of the maximum frequency is determined by the condition that the total number of oscillations is 3N (we neglect the energy discreteness) and 
, s is the speed of the wave. We assume that the speeds c l and c t are equal. Characteristic Debye temperature Q D = hn m / k.
We introduce x = hn/kT. The average vibration energy then at maximum
The second term under the integral will give E zero vibrations E o \u003d (9/8) NkQ D and then the vibrational energy of the crystal: 
Since U o and E o do not depend on T, the contribution to the heat capacity will give the 2nd term in the expression for energy.
We introduce the Debye function 
At high T, we obtain the obvious D(x) ® 1. Differentiating with respect to x, we obtain 
.
At high T limit C V = 3Nk, and at low: 
.
At small T, the upper limit of integration tends to infinity, E - E o = 3Rp 4 T 4 /5Q D 3 and we get the formula for determining C v at T® 0: where
Got Debye's law of cubes.
Debye's cube law.
The characteristic Debye temperature depends on the density of the crystal and the speed of propagation of oscillations (sound) in the crystal. The strict Debye integral must be solved on a computer.
Characteristic Debye temperature (Phys. encyclopedia)
Na 150 Cu 315 Zn 234 Al 394 Ni 375 Ge 360 Si 625
A.U 157 342 316 423 427 378 647
Li 400 K 100 Be 1000 Mg 318 Ca 230 B 1250 Ga 240
As 285 Bi 120 Ar 85 In 129 Tl 96 W 310 Fe 420
Ag 215 Au 170 Cd 120 Hg 100 Gd 152 Pr 74 Pt 230
La 132 Cr 460 Mo 380 Sn(white) 170, (grey) 260 C(diamond) 1860
To estimate the characteristic Debye temperature, you can use the Lindemann empirical formula: Q D \u003d 134.5 [Tmelt / (AV 2/3)] 1/2, here A is the atomic mass of the metal. For the Einstein temperature, it is similar, but the 1st factor is taken as 100.
Debye's Achievements
Debye is the author of fundamental works on the quantum theory of solids. In 1912, he introduced the concept of a crystal lattice as an isotropic elastic medium capable of vibrating in a finite frequency range (Debye's solid body model). Based on the spectrum of these oscillations, he showed that at low temperatures the heat capacity of the lattice is proportional to the cube of the absolute temperature (Debye's heat capacity law). As part of his model of a solid body, he introduced the concept of a characteristic temperature at which quantum effects become significant for each substance (the Debye temperature). In 1913 one of Debye's most famous works was published, devoted to the theory of dielectric losses in polar liquids. Around the same time, his work on the theory of X-ray diffraction was published. The beginning of Debye's experimental activity is connected with the study of diffraction. Together with his assistant P. Scherrer, he obtained an X-ray diffraction pattern of finely ground LiF powder. Rings were clearly visible in the photograph, resulting from the intersection of X-rays, diffracted from randomly oriented crystals along the generatrix of the cones, with photographic film. The Debye-Scherrer method, or powder method, has long been used as the main method in X-ray diffraction analysis. In 1916, together with A. Sommerfeld, Debye applied the quantization conditions to explain the Zeeman effect and introduced the magnetic quantum number. In 1923 he explained the Compton effect. In 1923, Debye, in collaboration with his assistant E. Hückel, published two large articles on the theory of electrolyte solutions. The ideas presented in them served as the basis for the theory of strong electrolytes, which was called the Debye-Hückel theory. From 1927, Debye's interests focused on questions of chemical physics, in particular on the study of the molecular aspects of the dielectric behavior of gases and liquids. He also studied the diffraction of X-rays by isolated molecules, which made it possible to determine the structure of many of them.
Debye's main research interests during his time at Cornell University were polymer physics. He developed a method for determining the molecular weight of polymers and their shape in solution, based on the measurement of light scattering. One of his last major works (1959) was devoted to an issue that is extremely relevant even today - the study of critical phenomena. Among Debye's awards are the medals of H. Lorenz, M. Faraday, B. Rumford, B. Franklin, J. Gibbs (1949), M. Planck (1950) and others. Debye died in Ithaca (USA) on November 2, 1966.
Debye, an outstanding representative of Dutch science, received the Nobel Prize in Chemistry in 1936. Possessing exceptional versatility, he made a great contribution to the development of not only chemistry, but also physics. These merits brought Debye great fame; he was awarded the honorary title of Doctor of Science by more than 20 universities in the world (Brussels, Oxford, Brooklyn, Boston and others). He was awarded many medals and prizes, including Faraday, Lorentz. Plank. Since 1924, Debye - Corresponding Member. Academy of Sciences of the USSR.
Law cube iv Debye”, at vіdpovіdnostі z yakim. ... space). Vіdpovіdnі laws savings (as well as law saving electric charge) є ...
Basic understanding laws chemistry. Lecture notes
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If 5155 J of heat was transferred to one mole of a diatomic gas and the gas did work equal to 1000 J, then its temperature increased by ………….. K. (the bond between atoms in a molecule is rigid)
The change in the internal energy of the gas occurred only due to the work
gas compression in………………………………..process.
adiabatic
Longitudinal waves are
sound waves in the air
Resistance R, inductor L \u003d 100 H and capacitor C \u003d 1 μF are connected in series and connected to an alternating voltage source that varies according to the law
The loss of alternating current energy per period on the capacitor in the circuit of the electrical circuit is equal to .............................. (W)
If the efficiency of the Carnot cycle is 60%, then the temperature of the heater is greater than the temperature of the refrigerator in ………………………… times (a).
Entropy of an isolated thermodynamic system…………..
cannot decrease.
The figure schematically shows the Carnot cycle in coordinates. The increase in entropy takes place in the area ……………………………….
The unit of measurement for the amount of a substance is ..........
Isochores of an ideal gas in P-T coordinates are ..
The isobars of an ideal gas in V-T coordinates are ....
POST INCORRECT STATEMENT
The greater the inductance of the coil, the faster the capacitor discharges.
If the magnetic flux through a closed loop increases uniformly from 0.5 Wb to 16 Wb in 0.001 s, then the dependence of the magnetic flux on time t has the form
1.55*10v4t+0.5v
The oscillatory circuit consists of an inductor L = 10 H, a capacitor C = 10 μF and a resistance R = 5 Ohm. The quality factor of the circuit is equal to ……………………………
One mole of an ideal monatomic gas received 2507 J of heat during some process. At the same time, its temperature decreased by 200 K. The work done by the gas is equal to …………………………J.
An ideal monatomic gas in an isobaric process is supplied with the amount of heat Q. At the same time, ..........……% of the supplied amount of heat is spent to increase the internal energy of the gas
If we do not take into account the vibrational motions in the carbon dioxide molecule, then the average kinetic energy of the molecule is equal to ……………
POST INCORRECT STATEMENT
The greater the inductance in the oscillatory circuit, the greater the cyclic frequency.
The maximum efficiency value that a heat engine with a heater temperature of 3270 C and a refrigerator temperature of 270 C can have is …………%.
The figure shows the Carnot cycle in coordinates (T,S), where S is the entropy. Adiabatic expansion occurs in the area ………………………..
The process depicted in the figure in coordinates (T,S), where S is the entropy, is……………………
adiabatic expansion.
The equation for a plane wave propagating along the OX axis has the form The wavelength (in m) is ...
The voltage on the inductor from the strength of the current in phase ..............................
Leads by PI/2
Resistor with resistance R = 25 Ohm, coil with inductance L = 30 mH and capacitor with capacitance
C= 12 uF are connected in series and connected to an AC voltage source that varies according to the law U = 127 cos 3140t. The effective value of the current in the circuit is ……………A
The Clapeyron-Mendeleev equation is as follows…….
POST INCORRECT STATEMENT
The self-induction current is always directed towards the current, the change of which generates the self-induction current
The equation of a plane sinusoidal wave propagating along the OX axis has the form. The amplitude of the acceleration of oscillations of the particles of the medium is equal to ....................................
T6.26-1 Indicate the incorrect statement
The vector E (strength of the alternating electric field) is always antiparallel to the vector dE/dT
Maxwell's equation, which describes the absence of magnetic charges in nature, has the form
If we do not take into account vibrational motions in a hydrogen molecule at a temperature of 100 K, then the kinetic energy of all molecules in 0.004 kg of hydrogen is equal to…………………….J
Two moles of a hydrogen molecule were given 580 J of heat at constant pressure. If the bond between the atoms in the molecule is rigid, then the temperature of the gas has increased by ……………….K
The figure shows the Carnot cycle in coordinates (T, S), where S is the entropy. Isothermal expansion occurs in the area …………………
In the process of reversible adiabatic cooling of a constant mass of an ideal gas, its entropy ……………
does not change.
If a particle with a charge of which moves in a uniform magnetic field with induction B along a circle of radius R, then the momentum modulus of the particle is equal to
