NCERT Solutions for Class 11 Chemistry Chapter 5 - States of Matter

Question 1:

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

Question 2:

A vessel of 120 ml capacity contains a certain amount of gas at 35°C and 1.2 bar pressure. The gas is transferred to another vessel of volume 180 ml at 35°C. What would be its pressure ?

Question 3:

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

Question 4:

At 0°C, the density of a gaseous oxide at 2 bar is same as that of nitrogen at 5 bar. What is the molar mass of the oxide ?

Question 5:

Pressure of 1 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 a relationship between their molecular masses.

Question 6:

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

Question 7:

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

Question 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 oxygen at 0.7 bar are introduced in 1L vessel at 27°C ?

Question 9:

Density of a gas is found to be 5.46 g/dm3 at 27°C and 2 bar pressure. What will be its density at S.T.P. ?

Question 10:

340.05 ml of phosphorus vapours weigh 0.0625 g at 546°C and 0.1 bar pressure. What is the molar mass of phosphorus ?

Question 11:

A student forgot to add the reaction mixture to the round bottomed flask at 27°C but put it on the flame. After a lapse of time, he realised his mistake using a pyrometer he found the temperature of flask was 477°C. What fraction of air would have been expelled out ?

Question 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)

Question 13:

Calculate the total number of electrons present in 1.4 g of nitrogen gas.

Question 14:

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

Question 15:

Calculate the total pressure in a mixture of 8 g of oxygen and 4 g hydrogen, confined in a vessel of 1 dm3 at 27°C. R = 0.083 bar dm3 k–1 mol–1

Question 16:

Pay load is defined as the difference between the mass of displaced air and the mass of 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).

Question 17:

Calculate the volume occupied by 8.8 g of CO2 at 31.1°C and 1 bar pressure. R = 0.083 bar L K–1 mol–1

T = 31.1°C = 273 + 31.1 = 304.1 K

Question 18:

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

Question 19:

A mixture of hydrogen and oxygen at one bar pressure contains 20% by weight of hydrogen. Calculate the partial pressure of hydrogen.

Question 20:

What would be the SI unit for the quantity PV2T2/n ?

Question 21:

In terms of Charles’s law explain why – 273°C is the lowest possible temperature.

Question 22:

Critical temperature for carbon dioxide and methane are 31.1° C and – 81.9° C respectively. Which of these has stronger intermolecular forces and why ?