NCERT Solutions for Class 11 Chemistry Chapter 5 States of Matter: Download Questions & Answers PDF

MCQs:

5.28. The average kinetic energy of the gas molecule is

(a) Inversely proportional to its absolute temperature

(b) Directly proportional to its absolute temperature

(c) Equal to the square of its absolute temperature

(d) All of the above

5.29. At constant temperature, the pressure of the gas is reduced to one-third, the volume

(a) Reduce to one-third

(b) Increases by three times

(c) Remaining the same

(d) Cannot be predicted

5.32. Which of the following gases will have the lowest rate of diffusion?

(a) H₂

(b) N₂

(c) F₂

(d) O₂

5.10. 34.05 mL of phosphorus vapour weighs 0.0625 g at 546°C and 1.0 bar pressure. What is the molar mass of phosphorus?

5.30. With rise in temperature, the surface tension of a liquid

(a) Decreases 

(b) Increases

(c) Remaining the same

(d) None of the above

5.1. What will be the minimum pressure required to compress 500 dm³ of air at 1 bar to 200 dm³ at 30°C?

5.42.  State and explain Dalton’s law of partial pressures. Can we apply Dalton’s law of partial pressures to a mixture of carbon monoxide and oxygen?

5.17. Calculate the volume occupied by 8.8 g of CO₂ at 31.1 °C and 1 bar pressure. R = 0.083 bar LK^-1 mol^-1

5.6. The drain cleaner, Drainex contains small bits of aluminium which react with caustic soda to produce dihydrogen. What volume of dihydrogen at 20 °C and one bar will be released when 0.15g of aluminium reacts?

5.40. (a) What do you mean by Surface Tension of a liquid?

(b) Explain the factors which can affect the surface tension of a liquid.

5.18. 2.9 g of a gas at 95°C occupied the same volume as 0.184 g of hydrogen at 17°C at the same pressure. What is the molar mass of the gas?

5.7. What will be the pressure exerted by a mixture of 3.2g of methane and 4.4g of carbon dioxide contained in a 9 dm³ flask at 27 °C?

5.12. Calculate the temperature of 4.0 moles of a gas occupying 5 dm³ at 3.32 bar (R = 0.083 bar dm³ K^-1 mol^-1).

5.14. How much time would it take to distribute one Avogadro number of wheat grains if 10¹⁰ grains are distributed each second?

Assertion and Reason:

Directions:

(a) Assertion and reason both are correct statements and reason is correct explanation for assertion.

(b) Assertion and reason both are correct statements but reason is not correct explanation for assertion.

(c) Assertion is correct statement but reason is wrong statement.

(d) Assertion is wrong statement but reason is correct statement.

5.23. Assertion: The dipole-dipole interactionbetween two HCl moleculesis stronger than the London forces.

Reason: Only partial charges are involved

5.26. Assertion: Intermolecular interactions may hold the closely and slowly moving molecules together and thus the solid liquifies.

Reason: Compression brings the molecules in close vicinity and cooling slows down the movement of molecules.

5.19. A mixture of dihydrogen and dioxygen at one bar pressure contains 20% by weight of dihydrogen. Calculate the partial pressure of dihydrogen.   

5.31. Viscosity of a liquid is a measure of

(a) Repulsive forces between the liquid molecules

(b) Frictional resistance

(c) Intermolecular forces between the molecules

(d) None of the above

5.15. Calculate the total pressure in a mixture of 8g of oxygen and 4g of hydrogen confined in a vessel of l dm³ at 27°C. R = 0.083 bar dm³ K^-1 mol^-1.    

5.16. Pay load is defined as the difference between the mass of the displaced air and the mass of the balloon. Calculate the pay load when a balloon of radius 10 m, mass 100 kg is filled with helium at 1.66 bar at 27°C (Density of air = 1.2 kg m^-3 and R = 0.083 bar dm³ K^-1 mol^-1).

5.3. Using the equation of state PV= nRT, show that at a given temperature, density of a gas is proportional to the gas pressure P.

5.8. What will be the pressure of the gas mixture when 0.5 L of H₂ at 0.8 bar and 2.0 L of dioxygen at 0.7 bar are introduced in all vessel at 27 °C?

5.22. Critical temperature for CO₂ and CH₄ are 31.1°C and -81.9°C respectively. Which of these has stronger intermolecular forces and why?

5.27. Assertion: At high altitudes, liquids boil at lower temperatures in comparison to that at sea level.

Reason: At high altitudes atmospheric pressure is high.

5.24. Assertion: Viscosity of liquids decreases as the temperature rises.

Reason: Molecules of liquids are held together by attractive intermolecular forces.

5.25. Assertion: Liquids and solids are hard to compress.

Reason: Magnitude of the repulsion rises very rapidly as the distance separating the molecules decreases.

5.41. What are ideal and real gases? Out of CO₂ and NH₃ gases, which is expected to show more deviation from the ideal gas behaviour.

5.5. Pressure of l g of an ideal gas A at 27°C is found to be 2 bar. When 2 g of another ideal gas B is introduced in the same flask at same temperature, the pressure becomes 3 bar. Find the relationship between their molecular masses.