#### Thermodynamics Model Question Paper

11th Standard

Reg.No. :
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Chemistry

Time : 01:00:00 Hrs
Total Marks : 50
10 x 1 = 10
1. All the naturally occurring processes proceed spontaneously in a direction which leads to

(a)

decrease in entropy

(b)

increase in enthalpy

(c)

increase in free energy

(d)

decrease in free energy

2. Heat of combustion is always

(a)

positive

(b)

negative

(c)

zero

(d)

either positive or negative

3. Change in internal energy, when 4 kJ of work is done on the system and 1 kJ of heat is given out by the system is

(a)

+1 kJ

(b)

- 5 kJ

(c)

+3 kJ

(d)

- 3 kJ

4. The bond dissociation energy of methane and ethane are 360 kJ mol-1 and 620 kJ mol-1 respectively. Then, the bond dissociation energy of C-C bond is

(a)

170 kJ mol-1

(b)

50 kJ mol-1

(c)

80 kJ mol-1

(d)

220 kJ mol-1

5. Which among the following is not an extensive property?

(a)

Volume

(b)

internal energy

(c)

Mass

(d)

temperature

6. Which among the following is not a state function?

(a)

Pressure

(b)

Volume

(c)

Temperature

(d)

Work

7. Which among the following is a state function?

(a)

Pressure

(b)

Enthalpy

(c)

Heat

(d)

Both (a) and (b)

8. In a compression process, Pext is -----

(a)

(Pint+ dP)

(b)

(Pint- dP)

(c)

(dP-Pint)

(d)

(-Pint+dP)

9. ΔHo of H2O(1) is KJ/mol.

(a)

-74.85

(b)

-242

(c)

+242

(d)

+74.85

10. Heat absorbed at constant volume is measured in ------- calorimeter.

(a)

Coffee cup

(b)

Differential scanning

(c)

Bomb

(d)

11. 5 x 2 = 10
12. State the first law of thermodynamics.

13. Define Gibb's free energy.

14. Identify the state and path function out of the following: a) Enthalpy b) Entropy c) Heat d) Temperature e) Work f) Free energy.

15. Give examples for extensive and intensive properties.

16. Explain Zeroth law of thermodynamics.

17. 5 x 3 = 15
18. What are state and path functions? Give two examples

19. In a constant volume calorimeter:3.5g of a gas with molecular weight 28 was burnt in excess oxygen at 298 K. The temperature of the calorimeter was found to increase from 298 K to 298.45 K due to the combustion process. Given that the calorimeter constant is 2.5 kJ K-1. Calculate the enthalpy of combustion of the gas in kJ mol-1

20. For a reaction, 2Cl(g) ⟶ Cl2, What are the signs of ΔH and ΔS?

21. In the equation N2(g)+ 3H2(g) ⇌2NH3(g) What would be the sign of work done?

22. Which law of thermodynamics deals with equivalence of different forms of energies?

23. 2 x 5 = 10
24. List the characteristics of internal energy.

25. For the equilibrium ${ PCl }_{ 5 }\rightleftharpoons { PCl }_{ 3(g) }+{ Cl }_{ 2(g) }$ at 298 K, K is 1.8 x 10-7. What is the ΔG0 for the reaction?