Class 11 Chemistry — Chapter 5: States of Matter Online Test

1. A rigid vessel at contains mol and mol . An electric spark causes complete reaction . After cooling back to , what is the final pressure?

2. Which property makes supercritical fluids useful as solvents in industry?

3. Which curve best represents the relation between vapour pressure and temperature?

4. What is the critical temperature of CO₂ observed in Andrews’ experiments?

5. The van der Waals constant has which units (for 1 mol gas)?

6. Why is added to pressure in the van der Waals equation?

7. At very low pressure, the compressibility factor of a real gas approaches:

8. If for a gas, it means:

9. If hydrogen () has an RMS speed of 1840 m/s at a given temperature, what is the RMS speed of oxygen () at the same temperature?

10. Which relation connects pressure, volume, and average kinetic energy of molecules?

11. Which constant directly connects molecular kinetic energy with absolute temperature?

12. Which assumption of kinetic theory explains the compressibility of gases?

13. Which of the following statements is correct about Dalton’s law?

14. If 3 L of nitrogen gas contains molecules at constant T and P, how many molecules will 6 L of nitrogen contain?

15. Which statement is true about Avogadro’s number ()?

16. The graph of Gay Lussac’s law (Pressure vs Temperature) is:

17. Which everyday example best demonstrates Charles’ law?

18. Boyle’s law is valid under which condition?

19. Which has stronger intermolecular forces: or ?

20. The correct order of diffusion rate at room temperature is:

1. The bends (decompression sickness) in divers is caused mainly due to:

2. The supercritical fluid region in Andrews’ isotherms lies:

3. The coefficient of volume expansion is generally in the order:

4. What causes dipole–dipole interaction strength to increase?

5. Which property best explains why iodine () has a higher melting point than fluorine ()?

6. When ammonia and hydrogen chloride gases diffuse toward each other, a white ring of forms closer to HCl because:

7. The phenomenon of vapour pressure lowering is responsible for:

8. The Boyle temperature of a gas is defined as:

9. In scuba diving, the composition of compressed air cylinders must consider Dalton’s law because:

10. If a gas mixture contains 3 mol of , 1 mol of , and 2 mol of , and total pressure is 6 atm, what is the partial pressure of ?

11. For a non-polar gas like helium, deviation from ideality is mainly due to:

12. Which relation connects pressure and average kinetic energy of molecules?

13. A supercritical fluid is defined as:

14. Which of the following pairs of quantities always remain constant in Boyle’s law?

15. The compressibility factor is defined as:

16. How many liters of nitrogen gas at STP contain molecules?

17. Which expression connects compressibility factor with molar volume?

18. Why does kinetic theory assume intermolecular forces are negligible in gases?

19. Why does methane () have a very low boiling point?

20. For a van der Waals gas, the compressibility factor at the critical point is:

21. Which type of intermolecular force is most significant in liquid ?

22. Which critical property determines whether a gas can be liquefied at room temperature (298 K)?

23. Which real-life application is based on the concept of viscosity?

24. The mathematical form of Gay Lussac’s law is:

25. The average speed of gas molecules is given by:

26. Which phenomenon in plants is partially explained by surface tension?

27. Which intermolecular force is the weakest?

28. 2 g of H₂ and 16 g of O₂ are kept in the same 10 L vessel at 300 K. Calculate the ratio of their partial pressures.

29. Which of the following increases with addition of surfactants in water?

30. Which statement about densities is correct?

1. A given gas occupies 200 mL at 740 mmHg. What volume will it occupy at 760 mmHg, assuming constant T?

2. Gay Lussac’s law states that for a fixed mass of gas at constant volume:

3. Why does carbon dioxide show greater deviation than nitrogen at the same conditions?

4. Why is ion–dipole force stronger than dipole–dipole force?

5. Which of the following equations is derived from Charles’ law?

6. Which condition favors ideal behavior most strongly?

7. Which state has the largest bulk modulus (thus the least compressible)?

8. 2 g of H₂ and 16 g of O₂ are placed in a 5 L vessel at 300 K. What is the total pressure? ().

9. The constant obtained in Boyle’s law, , depends on:

10. Which factor is more significant at low pressure?

11. Why do small liquid drops form spherical shapes?

12. Why does high pressure promote liquefaction of gases?

13. Which condition leads to higher total thermal energy?

14. Hydrogen diffuses four times faster than which of the following gases?

15. The coefficient of volume expansion is generally in the order:

16. Which of the following is assumed to remain constant during molecular collisions in kinetic theory?

17. A gas mixture contains 2 mol of O₂, 3 mol of N₂, and 1 mol of CO₂ in a 20 L container at 300 K. Calculate the total pressure and the partial pressure of CO₂. ( L·atm·K⁻¹·mol⁻¹)

18. Why does a soft drink fizz more when opened at room temperature compared to when it is chilled?

19. Which gas law explains why helium is preferred to nitrogen in deep-sea diving gas mixtures?

20. Boyle’s law is valid under which condition?

21. Which experiment confirmed Avogadro’s hypothesis?

22. Which type of intermolecular force exists in all substances, regardless of polarity?

23. A balloon filled with air at 1 atm has a volume of 2.5 L. If the balloon is squeezed until volume becomes 1.25 L, the new pressure inside will be:

24. What happens to the volume of a gas if temperature is reduced to half at constant pressure?

25. The van der Waals equation for real gases is:

26. Why do molecular solids like naphthalene have relatively low melting points compared to ionic solids?

27. For a van der Waals gas, the compressibility factor at the critical point is:

28. Which state of matter has definite volume but no definite shape?

29. Which of the following increases with addition of surfactants in water?

30. The phenomenon of vapour pressure lowering is responsible for:

31. Which state of matter results when intermolecular forces greatly exceed thermal energy?

32. Which everyday example best demonstrates Charles’ law?

33. Which of the following pairs of quantities always remain constant in Boyle’s law?

34. For a real gas, indicates:

35. Which statement about densities is correct?

36. The heat absorbed during the conversion of 1 mole of ice at to water at is called:

37. Which of the following is not an assumption of the kinetic theory of gases?

38. Which of the following is an example of conversion of thermal energy to mechanical energy?

39. Which of the following best describes the cause of deviation in van der Waals equation?

40. Which intermolecular force plays the major role in dissolving NaCl in water?

41. Why are liquid crystals important in modern technology?

42. Why do real gases deviate from ideal behavior at low temperature?

43. Which row correctly matches “shape–volume” for the three states?

44. The critical pressure () is defined as:

45. If gas A has molar mass 4 and gas B has molar mass 64, the ratio of their diffusion rates () is:

46. A 10 g sample of helium occupies 5.6 L at STP (273 K, 1 atm). Using ideal gas law, calculate molar mass of helium.

47. Which of the following statements about liquid crystal displays (LCDs) is correct?

48. What volume will mol occupy at and ?

49. A mixture of 2 mol , 3 mol , and 5 mol exerts 9 atm total pressure. The partial pressure of is:

50. A balloon has a volume of 2.5 L at 20°C. At what temperature will it occupy 5.0 L, assuming pressure is constant?