__States of Matter Class 11 Numericals__

States of Matter Class 11 Numericals

**Que 1. Calculate the temperature of 4.0 moles of gas occupying 5 dm ^{3} volume at 3.32 bar. (R= 0.083 bar dm^{3} k^{-1} mol^{-1}).**

**Ans 1.**PV = nRT

T = PV/nR

**Que 2. A sample of gas occupies 100 dm ^{3} at 1 bar pressure and at 0^{0}C. If the volume of the gas is reduced to 5 dm^{3} at the same temperature, what additional pressure must be applied?**

**Ans 2.**

**Que 3. A mixture of dihydrogen and dinitrogen at 1 bar pressure contains 20% by weight of H _{2}. Calculate the partial pressure of H_{2}.**

**Ans 3.**The mixture of H

_{2}and O

_{2}contains 20% H

_{2}means 20 gm H

_{2}& 80 gm O

_{2}

**Que 4. A certain amount of gas at 27 ^{0}C and bar pressure occupy a volume of 25 m^{3}. If the pressure is kept constant and the temperature is raised to 77 ^{0}C, what will be the volume of the gas?**

**Ans 4.**We know,

V

_{1}T

_{1}= V

_{2}T

_{2}

V

_{1}= 25 m

^{3}

T

_{1} = 27

^{0}C = 300 K

T

_{2} = 77

^{0}C = 350 K

Hence,

V

_{2}= 25 × 350/300

V

_{2}= 5 × 35/6

V

_{2}= 175/6

V

_{2}= 29.1 dm

^{3}

**Que 5. An O _{2} cylinder has 10 L O_{2} at 200 atm. It patient takes 0.50 ml of O_{2} at 1 atm in one breath at 37 ^{0}C. How many breaths are possible? **

**Ans 5.**10 L at 200 atm = ? L at 1 atm

P

_{1}V

_{1}= P

_{2}V

_{2}

200 × 10 = 1 × V

_{2}

V

_{2}= 2000 L,

**Que 6. An open vessel at 27 ^{0}C is heated until three-fifth of the air has been expelled. Assuming that the volume of air is constant. Find the temperature to which vessel has been heated.**

**Ans 6.**We know

**Que 7. Calculate the pressure exerted by 110 g of carbon dioxide in a vessel of 2 I. capacity at 37 ^{0}C. Given that the van der Waals constants are a = 3.59 L^{2} atm mol^{-2} and b = 0.0427 L mol^{-1}. Compare the value with the calculated value if the gas were considered ideal.**

**Ans 7.**According to van der Waals equation,

**Que 8. ****A vessel of volume 8 × 10 ^{-3} contains an ideal gas at 300 K and 210 kPa. The gas is allowed to leak till the pressure falls to 135 kPa. Calculate the amount of the gas leaked assuming the temperature to remain constant.**

**Ans 8.**There is no change in the volume and temperature of the gas during leakage. However, the number of moles of the gas or its mass changes.