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. For a system of particles, pressure from statistical mechanics is expressed as:

2. Which of the following has both ionic and covalent bonds?

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

4. For a monatomic ideal gas, the molar heat capacity at constant volume () is:

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

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

7. The adiabatic index for a monatomic gas is:

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

9. In statistical mechanics, first-order phase transitions are characterized by:

10. Which kinetic theory expression relates pressure to molecular speed distribution?

11. Which condition gives the smallest mean free path for a gas?

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

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

14. Which compound is held together by covalent bonding?

15. In an adiabatic expansion of 2 moles of a monatomic gas from 5 L to 20 L at 300 K, the final temperature is approximately:

16. White dwarfs in astrophysics are supported against gravitational collapse by:

17. Which phenomenon directly validates molecular speed distribution in gases?

18. In the Ising model, magnetization serves as:

19. For a diatomic molecule (ignoring vibrational modes), how many degrees of freedom are considered in equipartition theorem?

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

21. How does molecular diameter affect mean free path?

22. If a nanoparticle of radius is suspended in water () at room temperature (), calculate its diffusion coefficient.

23. Why does Einstein’s theory link Brownian motion to the second law of thermodynamics?

24. The use of catalysts in chemical kinetics primarily affects:

25. Which of the following explains why iodine () is solid at room temperature while chlorine () is a gas?

26. Which practical application directly uses the law of equipartition of energy?

27. What role did Einstein’s theory of Brownian motion play in physics history?

28. Collision theory states that a chemical reaction occurs when:

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

30. A gas mixture contains 2 moles of O and 4 moles of He at 300 K. Calculate ratio of rms speeds .

1. Why do liquids evaporate even at room temperature?

2. 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?

3. Which assumption connects kinetic theory to absolute temperature?

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

5. Boyle’s Law, one of the early gas laws, relates pressure and volume as:

6. The mean free path of a gas molecule is related to number density and molecular diameter as:

7. Which molecular property is directly measured by temperature according to kinetic theory?

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

9. Calculate most probable speed of hydrogen molecules at 300 K:

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

11. The mean free path for nitrogen at 300 K and 1 atm is . If viscosity , and is measured as , find approximate average molecular speed. Density .

12. The atomic number of an element represents:

13. A glass window area, thick, with separates inside and outside . Calculate heat loss per second.

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

15. The viscosity of a liquid can be determined using Poiseuille’s law for laminar flow through a capillary tube: If a capillary tube of radius and length allows a volume flow rate under a pressure difference of , calculate the viscosity of the liquid.

16. Why is mean free path important in determining thermal conductivity of gases?

17. Why are catalysts widely used in chemical industries?

18. Which type of intermolecular force is primarily responsible for the high boiling point of water?

19. In a mixture of hydrogen and oxygen at 300 K, the ratio of mean speeds is:

20. Calculate the ratio of diffusion rates of helium (M = 4) and nitrogen (M = 28).

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

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

23. Which type of bond explains the malleability and ductility of metals?

24. The specific heat of helium at constant volume is closest to:

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

26. For 1 mole of an ideal gas, the total translational kinetic energy is:

27. In the Ising model, magnetization serves as:

28. Which equation relates diffusion coefficient to mean free path?

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

30. Which scientist discovered the neutron?

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

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

33. If a gas occupies 4 L at 2 atm pressure, what volume will it occupy at 1 atm, assuming constant temperature?

34. How does kinetic theory explain the pressure exerted by liquids in a container?

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

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

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

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

39. The macroscopic quantity pressure in a gas arises microscopically from:

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

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

42. If the pressure of a gas is reduced to half at constant temperature, what happens to mean free path?

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

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

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

46. In engineering insulation problems, effective thermal conductivity for multilayer walls is found by:

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

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

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

50. For an ideal gas, the relation between and is given by: