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. How does pressure affect the mean free path of a gas?

2. Why are catalysts widely used in chemical industries?

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

4. A 10 L container holds 0.5 mol of O at 300 K. Calculate pressure using kinetic theory:

5. Which of the following is a characteristic property of metallic bonds?

6. The latent heat equation during condensation of a mass of vapor is:

7. Catalysts are essential in catalytic converters because they:

8. Light can increase the rate of some chemical reactions (photochemical reactions) because:

9. A sample of oxygen () is at 300 K. Calculate its rms speed.

10. Why does kinetic theory correctly predict viscosity of gases but not liquids?

11. The ratio of specific heats () for a diatomic gas at moderate temperature is approximately:

12. The relation between average kinetic energy per molecule and temperature is:

13. In a Boyle’s law experiment, a gas sample initially at 1 atm and 500 mL is compressed to 250 mL. What is the new pressure?

14. The molar heat capacity at constant volume, , for a diatomic gas (ignoring vibrations) is:

15. Why does ethanol () dissolve in water?

16. From a statistical mechanics perspective, a phase transition occurs when:

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

18. How does kinetic theory help explain the states of matter?

19. In the upper atmosphere, mean free path of molecules is very large because:

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

21. If a wall of thickness and conductivity separates indoors at from outdoors at , calculate heat loss per square meter per second.

22. Which term in the Van der Waals equation accounts for molecular attractions?

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

24. For 2 moles of a monatomic ideal gas, calculate the increase in internal energy when temperature increases by 50 K.

25. In Lee’s disc experiment, if brass disc of heat capacity cools at , calculate heat flow through the sample.

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

27. Why does liquefaction of gases occur in real gases but not in ideal gases?

28. Why is boiling considered a first-order phase transition?

29. Which ensemble is used for a system at fixed temperature, volume, and number of particles?

30. Who introduced the statistical interpretation of entropy and molecular distribution of speeds?

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

2. If a wall of thickness and conductivity separates indoors at from outdoors at , calculate heat loss per square meter per second.

3. Which real-world process is based on gas effusion?

4. For a diatomic gas (ignoring vibrational energy), the molar heat capacity at constant volume is:

5. Which compound is held together by covalent bonding?

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

7. Why do correlation lengths diverge near second-order transitions?

8. The internal energy of an ideal monatomic gas is expressed microscopically as:

9. Why does a monatomic ideal gas have ?

10. Which equation links diffusion coefficient of nanoparticles to temperature, radius, and viscosity, and is used in nanotechnology research?

11. The formula for mean free path is:

12. Which scientist proposed corrections to the ideal gas law to account for real gas behavior?

13. A steel sphere of radius falls through oil of density . The sphere density is , terminal velocity . Find viscosity of oil.

14. If 3 moles of a gas occupy 67.2 L at STP, then the volume of 1 mole of the gas is:

15. Which of the following statements about ionic bonds is correct?

16. How does pressure affect the mean free path of a gas?

17. The failure of equipartition theorem at very low temperatures is explained by:

18. What does the Maxwell-Boltzmann distribution describe in relation to thermodynamics?

19. Calculate the molar heat capacity ratio () for a monatomic ideal gas.

20. In nuclear emulsions, Brownian-like motion of ions can be modeled using which formula?

21. If temperature of a gas is doubled (in Kelvin), its rms speed will:

22. Which of the following graphs correctly represents Charles’s law?

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

24. According to kinetic theory, the volume of individual gas molecules compared to the total volume of the gas is:

25. For a monatomic ideal gas, what is the value of ?

26. If the diameter of molecules is halved while keeping pressure and temperature constant, the mean free path will:

27. Which of the following is a property of covalent compounds?

28. Which relation connects diffusion coefficient , mean free path , and molecular speed ?

29. The dimension of thermal conductivity in SI units is:

30. Calculate mean free path of nitrogen at , . (Molecular diameter , ).

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

32. The most probable speed of gas molecules is given by:

33. At sea level (1 atm, 300 K), the mean free path of air molecules is approximately:

34. Why are gases highly compressible compared to solids and liquids?

35. Who is credited with developing the kinetic theory of gases in its modern form?

36. Which of the following statements best summarizes the effect of temperature and pressure on mean free path?

37. A gas has a volume of 500 mL at 20°C. What will be its volume at 0°C at constant pressure?

38. For a gas with molecular diameter , at , and , calculate the mean free path.

39. Why does compressibility factor deviate from 1 for real gases?

40. A nanoparticle of radius undergoes Brownian motion. If the viscosity of the medium is doubled, how does diffusion coefficient change?

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

42. The molar specific heat at constant volume is defined as:

43. For a linear triatomic molecule at high temperature, the expected using kinetic theory is:

44. Why does ice float on water in terms of phase transition properties?

45. At very high altitudes, the mean free path of air molecules is extremely large because:

46. Why are neutron stars denser than white dwarfs?

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

48. Which of the following is a characteristic property of metallic bonds?

49. The Clausius–Clapeyron equation predicts that vapor pressure varies approximately as:

50. What is the primary reason ionic compounds conduct electricity in molten state but not in solid state?