#### Gaseous State Book Back Questions

11th Standard

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Chemistry

Time : 00:45:00 Hrs
Total Marks : 30
5 x 1 = 5
1. Gases deviate from ideal behavior at high pressure. Which of the following statement(s) is correct for non-ideality?

(a)

at high pressure the collision between the gas molecule become enormous

(b)

at high pressure the gas molecules move only in one direction

(c)

at high pressure, the volume of gas become insignificant

(d)

at high pressure the intermolecular interactions become significant

2. The temperatures at which real gases obey the ideal gas laws over a wide range of pressure is called

(a)

Critical temperature

(b)

Boyle temperature

(c)

Inversion temperature

(d)

Reduced temperature

3. The value of the gas constant R is

(a)

0.082 dm2 atm.

(b)

0.987 cal mol-1K-1

(c)

8.3 J mol-1 K-1

(d)

8 erg mol-1 K-1

4. Compressibility factor for CO2 at 400 K and 71.0 bar is 0.8697. The molar volume of CO2 under these conditions is

(a)

22.04 dm3

(b)

2.24 dm3

(c)

0.41 dm3

(d)

19.5 dm3

5. The variation of volume V, with temperature T, keeping pressure constant is called the coefficient of thermal expansion ie $\alpha =\frac { 1 }{ V } { \left( \frac { \partial V }{ \partial T } \right) }_{ P }$ . For an ideal gas a is equal to

(a)

T

(b)

1/T

(c)

P

(d)

none of these

6. 3 x 2 = 6
7. Aerosol cans carry clear warning of heating of the can. Why?

8. Why do astronauts have to wear protective suits when they are on the surface of moon?

9. When ammonia combines with HCI, NH4CI is formed as white dense fumes. Why do more fumes appear near HCI?

10. 3 x 3 = 9
11. Hydrochloric acid is treated with a metal to produce hydrogen gas. Suppose a student carries out this reaction and collects a volume of 154.4 x 10-3 dm3 of a gas at a pressure of 742 mm of Hg at a temperature of 298 K. What mass of hydrogen gas (in mg) did the student collect?

12. It takes 192 sec for an unknown gas to diffuse through a porous wall and 84 sec for N2 gas to effuse at the same temperature and pressure. What is the molar mass of the unknown gas?

13. A combustible gas is stored in a metal tank at a pressure of 2.98 atm at 25°C. The tank can withstand a maximum pressure of 12 atm after which it will explode. The building in which the tank has been stored catches fire. Now predict whether the tank will blow up first or start melting? (Melting point of the metal = 1100 K).

14. 2 x 5 = 10
15. Derive the values of vanderwaals equation constants in terms of critical constants.

16. A tank contains a mixture of 52.5 g of oxygen and 65.1 g of CO2 at 300 K the total pressure in the tanks is 9.21 atm. Calculate the. partial pressure (in atm.) of each gas in the mixture.