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. Collision theory states that a chemical reaction occurs when:

2. Thermal conductivity of copper is . A copper plate thick, area , has surfaces at and . Calculate heat current.

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

4. Which scientist first explained the cause of Brownian motion theoretically?

5. In thermodynamics, free energy determines spontaneity. Which statistical mechanics quantity helps calculate free energy?

6. A sample of gas has a volume of 250 mL at 300 K. To maintain constant pressure, what temperature is needed for the volume to expand to 500 mL?

7. In enzyme catalysis, the “lock and key model” explains:

8. Which assumption of kinetic theory is violated when gases show liquefaction at high pressure?

9. In Poiseuille’s method, if radius of capillary is doubled, volume flow rate of liquid changes by a factor of:

10. Which law can be derived from the kinetic theory assumption that average kinetic energy is proportional to absolute temperature?

11. If air at STP has molecular diameter and number density , calculate mean free path.

12. Which experimental observation best supports Avogadro’s law?

13. The molar volume of an ideal gas at STP (Standard Temperature and Pressure, 273 K and 1 atm) is:

14. Viscosity of a gas is related to mean free path by:

15. For a diatomic ideal gas (neglecting vibration), the molar heat capacity at constant pressure () is:

16. In a viscometer test, water takes 90 s to flow through a tube, while a liquid of density takes 150 s. If viscosity of water is , find viscosity of liquid.

17. A metal rod of length , cross-sectional area , and thermal conductivity is subjected to a temperature difference of . Calculate heat current through the rod.

18. Thermal conductivity of gases is explained by kinetic theory as:

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

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

21. What type of bond holds the atoms together in a diamond crystal?

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

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

24. The failure of classical predictions of specific heat at low temperatures is explained by:

25. Why does sodium chloride (NaCl) have a high melting point?

26. Which experiment provided evidence for the wave nature of electrons?

27. According to Bohr’s model, the angular momentum of an electron in orbit is quantized as:

28. If temperature rises from 300 K to 330 K, how does the rate constant typically change for a reaction with ?

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

30. Why does Maxwell–Boltzmann distribution predict that some molecules always exceed escape velocity from Earth?

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

2. In kinetic theory derivation, the temperature of a gas is defined in terms of:

3. Which scientist formulated the Atomic Theory in the early 19th century that laid the foundation for kinetic theory?

4. Calculate most probable speed of O molecules at 500 K:

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

6. Why is the factor included in the formula for mean free path?

7. The Maxwell–Boltzmann distribution provides a molecular basis for which thermodynamic law?

8. The heat flux through a wall is found experimentally to be for a temperature difference of across . Calculate thermal conductivity.

9. Which assumption connects kinetic theory to absolute temperature?

10. Which expression relates the rms speed of molecules to pressure and density?

11. The heat capacity ratio is important in which thermodynamic process?

12. Why are catalysts widely used in chemical industries?

13. In lubrication engineering, shear stress is given by Newton’s law: If oil film of viscosity and thickness separates two plates, one moving at , calculate shear stress.

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

15. If mean free path is proportional to , what happens to when temperature doubles and pressure halves?

16. Which industrial process uses finely divided platinum as a catalyst?

17. Which of the following compounds contains polar covalent bonds?

18. A sample of gas has a volume of 250 mL at 300 K. To maintain constant pressure, what temperature is needed for the volume to expand to 500 mL?

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

20. Why does pressure of a gas increase with temperature at constant volume?

21. In terms of kinetic theory, collision frequency () for two species is proportional to:

22. The Maxwell–Boltzmann distribution describes:

23. Which assumption of kinetic theory explains why pressure of a gas arises?

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

25. Boyle’s law states that for a fixed mass of gas at constant temperature:

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

27. Why does the viscosity of gases increase with temperature, unlike liquids?

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

29. In terms of Helmholtz free energy , entropy is calculated as:

30. The relation between molar heat capacity at constant pressure () and at constant volume () for ideal gases is:

31. Which of the following assumptions is true for an ideal gas but not for a real gas?

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

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

34. The order parameter in phase transitions represents:

35. A plane wall of thickness , area , and thermal conductivity has steady heat flow of 600 W. Calculate the temperature difference across the wall.

36. In a viscometer test, water takes 90 s to flow through a tube, while a liquid of density takes 150 s. If viscosity of water is , find viscosity of liquid.

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

38. A 100 nm gold nanoparticle in water has . What is its root mean square displacement in 1 second?

39. The Ostwald process for nitric acid production uses which catalyst?

40. The mean free path is inversely proportional to:

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

42. Which catalyst is used in the Haber process for ammonia synthesis?

43. 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.

44. Which experiment provided evidence for the wave nature of electrons?

45. Why does ethanol () dissolve in water?

46. At STP, calculate collision frequency of oxygen molecules. Take .

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

48. A steel plate of thickness , area , and thermal conductivity has temperatures of and on its two sides. Calculate the heat transfer rate.

49. For a monatomic ideal gas, which degrees of freedom contribute to its energy?

50. Which property of gases can be directly explained using the concept of mean free path?