Class 11 Physics — Chapter 13: Kinetic Theory Online Test

1. The escape velocity from Earth is . At what temperature would rms velocity of hydrogen molecules equal escape velocity? M = 0.002 kg/mol.

2. Reynolds number is given by: Air () flows at velocity through a pipe of diameter . Calculate Reynolds number.

3. For a cylindrical pipe of length , inner radius , outer radius , and , temperature difference is . Calculate heat transfer per second.

4. If nitrogen gas has mean free path and average molecular speed , calculate diffusion coefficient.

5. If the enthalpy of vaporization of liquid helium at 4.2 K is , calculate the entropy change per mole during vaporization.

6. A 250 g block of ice at 0 °C is converted into water at 0 °C. Find the entropy change of the system. (, )

7. The macroscopic law is derived microscopically using:

8. Entropy () connects microscopic and macroscopic descriptions by the relation:

9. The Boltzmann constant () relates:

10. According to Arrhenius equation , how does temperature affect rate constant?

11. In chemical engineering, the diffusion coefficient for gases is often estimated using kinetic theory as:

12. Why is Brownian motion critical in nanomedicine for drug delivery systems?

13. According to Einstein’s 1905 explanation, the random motion of suspended particles in Brownian motion is caused by:

14. The mean free path is inversely proportional to:

15. A gas has . If 5 moles of this gas are heated at constant volume through 40 K, how much heat is absorbed?

16. The work done by an ideal gas in an isothermal process from to is:

17. According to the law of equipartition, the average energy per molecule of a monatomic ideal gas is:

18. For a monatomic ideal gas, the total average energy per molecule according to equipartition theorem is:

19. What happens to the pressure of a gas if the rms speed of its molecules doubles at constant volume?

20. Which formula relates pressure , number density , molecular mass , and mean square speed ?

1. At 373 K, the enthalpy of vaporization of water is . Using Clausius–Clapeyron, calculate at 1 atm ().

2. The average speed of molecules in Maxwell–Boltzmann distribution is:

3. Who was the first scientist to propose that matter is made up of indivisible particles called “atoms”?

4. For 1 mole of a monatomic gas at temperature , the total internal energy is:

5. Specific heat capacity is related to microscopic states because:

6. In atmospheric escape processes, lighter gases like hydrogen are lost from Earth because:

7. The order of molecular speeds at a given temperature is:

8. According to Charles’s law, if absolute temperature of a gas decreases, its volume:

9. If nitrogen gas has mean free path and average molecular speed , calculate diffusion coefficient.

10. Calculate the relative rate of diffusion of nitrogen () to oxygen ().

11. A slab of glass of thickness has thermal conductivity . If the two surfaces are kept at and , calculate heat flow per unit area per second.

12. Thermal conductivity () of a material is defined by Fourier’s law of heat conduction:

13. Which of the following is NOT true for covalent bonds?

14. At a liquid–gas critical point, the order parameter vanishes. If density difference between phases is , then near critical temperature:

15. Which factor most strongly determines whether a bond is ionic or covalent?

16. The probability distribution of molecular speeds in a gas is given by:

17. In heterogeneous catalysis, why does increasing surface area of catalyst increase reaction rate?

18. The specific heat at constant volume of 1 mole of an ideal monatomic gas is:

19. Which property of a gas is directly proportional to the average kinetic energy of its molecules?

20. Brownian motion refers to:

21. Why do nanoparticles exhibit stronger Brownian motion than microparticles?

22. Calculate the entropy change when 1 mole of water vapor condenses at 373 K. ()

23. Pressure affects the rate of reaction most strongly in:

24. At 400 K, hydrogen molecules () have rms speed If , mean free path , calculate viscosity.

25. Calculate the heat required to raise the temperature of 3 moles of a diatomic gas (ignoring vibrations) by 50 K at constant pressure.

26. Which of the following speeds is NOT defined in the context of Maxwell–Boltzmann distribution?

27. Why do smaller suspended particles show more vigorous Brownian motion compared to larger ones?

28. Why is Brownian motion critical in nanomedicine for drug delivery systems?

29. According to Einstein’s 1905 explanation, the random motion of suspended particles in Brownian motion is caused by:

30. Calculate ratio of rms speeds of H and O at same temperature.

1. Using kinetic theory, show how viscosity relates to thermal conductivity . For monatomic gases: where is molar heat capacity at constant pressure. If for air and , calculate . (Molar volume at STP ).

2. According to equipartition theorem, what is the molar heat capacity at constant pressure () for a monatomic ideal gas?

3. Metallic bonds are best explained by which model?

4. Which type of bonding explains why aluminum is both strong and a good conductor of electricity?

5. Which equation derived by Einstein relates mean squared displacement in Brownian motion to time?

6. Kinetic theory assumes that collisions between gas molecules are:

7. A triatomic linear molecule like has how many degrees of freedom (ignoring vibrations)?

8. At 300 K, calculate diffusion coefficient of oxygen if mean free path = and average molecular speed = 480 m/s:

9. The specific heat capacity at constant volume of an ideal gas can be calculated using:

10. Brownian motion decreases in intensity when:

11. Which of the following is NOT an assumption of kinetic theory for an ideal gas?

12. In kinetic theory, what is the assumption about the size of gas molecules compared to the distance between them?

13. What is the main postulate of kinetic theory of gases?

14. At the critical point of a liquid–gas transition, the order parameter is:

15. Which distribution applies to indistinguishable particles with integer spin (photons, helium-4 atoms)?

16. A superconductor undergoes a second-order phase transition at critical temperature . The specific heat shows:

17. The specific heat at constant volume of 1 mole of an ideal monatomic gas is:

18. Which formula relates pressure , number density , molecular mass , and mean square speed ?

19. What does the steric factor in collision theory account for?

20. Which of the following is an example of an ionic bond?

21. At what conditions do real gases behave most like ideal gases?

22. Which scientist’s work finally unified the microscopic kinetic theory with macroscopic thermodynamics?

23. A wall of area , thickness , and conductivity separates rooms at and . Find heat loss per second.

24. A balloon at constant pressure shrinks in volume when cooled. Which molecular explanation fits Charles’s law?

25. Why is measuring viscosity important in engineering applications?

26. Which of the following best describes a polar covalent bond?

27. Why is Brownian motion critical in nanomedicine for drug delivery systems?

28. Which of the following does NOT affect the rate of a chemical reaction?

29. Diffusion of gases is defined as:

30. Which transport property of gases is NOT directly related to mean free path?

31. In a bimolecular reaction , the rate constant in collision theory is expressed as:

32. Which physical constant can be determined from analyzing Brownian motion data?

33. A glass capillary has length , radius . Under a pressure head of of water (), water () flows through it. Calculate volume flow rate.

34. According to kinetic theory, the distribution of molecular speeds in a gas:

35. In metallurgy, the Clausius–Clapeyron relation explains slope of solid–liquid equilibrium lines as:

36. Why must Charles’s law be expressed in Kelvin instead of Celsius?

37. Avogadro’s law provides direct evidence for which concept?

38. Which scientist first published the law of pressure-volume relationship (Boyle’s law)?

39. The root mean square displacement of a nanoparticle undergoing Brownian motion in time is given by:

40. The partition function in statistical mechanics is defined as:

41. Einstein’s explanation of Brownian motion is considered a bridge between:

42. Which experimental observation validates the Maxwell–Boltzmann distribution of molecular speeds?

43. The work done by an ideal gas in an isothermal process from to is:

44. Effusion is applied in separating isotopes in nuclear fuel processing. Which relation gives the separation factor between two isotopes of molar masses and ?

45. Who is credited with proposing the “plum pudding” model of the atom?

46. For 1 mole of diatomic gas (without vibrations), the molar heat capacity at constant pressure is:

47. Why does viscosity of the medium affect Brownian motion?

48. In the Ising model, magnetization serves as:

49. For 1 mole of a monatomic ideal gas at , calculate average translational kinetic energy per molecule and per mole. ()

50. If two gases and have molar masses and , the ratio of their rates of diffusion is: