Chemical Thermodynamics: Chemistry Free Online Mock Test 1

1. Which of the following always has a negative value?
(a) heat of reaction (b) heat of solution
(c) heat of combustion (d) heat of formation

2. A reaction, A + B—>C + D + q is found to have a positive entropy change. The reaction will be

3. The enthalpies of all elements in their standard states are : ‘
(i) unity (ii) zero
(iii) < 0 (iv) different for each element

4. For an endothermic reaction.
(a) ∆H is -ve (b) ∆H is +ve
(c) ∆H is zero (d) none of these

5. For the process to occur under adiabatic conditions, the correct condition is:
(i) ∆T= 0 (ii) ∆p = 0
(iii) q = 0 (iv)  w = 0

6. The enthalpy of combustion of methane, graphite and dihydrogen at 298 K are -890.3 KJ mol^-1, – 393.5 KJ mol^-1 and – 285.8 KJ mol^-1 respectively. Enthalpy of formation of CHJg) will be
(i) – 74.8 KJ mol^-1  (ii) – 52.27 KJ mol^-1
(iii) + 74.8 KJ mol^-1 (iv) + 52.26 KJ mol^-1

7. Calculate the standard enthalpy of formation of CH₃OH. from the following data in kj mol^-1:
(i) CH₃OH(l) + 3/2 0₂ (g) ———-> CO₂ (g) + 2H₂0 (l); ∆_rH^– = – 726kj mol^-1
(ii) C(s) + 0₂(g) —————>C0₂ (g); ∆_cH^– = -393 kj mol^-1
(iii) H₂(g) + 1/20₂(g) —————->H₂0 (l); ∆_fH^– = -286 kj mol^-1

8. Thermodynamics is applicable to
(a) macroscopic system only (b) microsopic system only
(c) homogeneous system only (d) heterogeneous system only

9. For a cyclic process, the change in internal energy of the system is
(A) always +ve (b) equal to zero
(c) always -ve (d) none of the above

10. Which of the following properties is not a function of state?
(a) concentration (b) internal energy
(c) enthalpy (d) entropy

11. The bond energy depends upon
(a) size of the atom (b) electronegativity
(c) bond length (d) all of the above

12. In a process, 701 ] of heat is absorbed by a system and 394 J of work is done by the system. What is the change in internal energy for the process?

13. The process depicted by the equation.
H₂O (S) ——> H₂O (l) ∆H = +1.43 kcal represents
(a) fusion (b) melting
(c) evaporation (d) boilirtg

14. A thermodynamic state junction is a quantity
(i) used to determine heat changes
(ii) whose value is independent of path
(iii) used to determine pressure volume work
(iv) whose value depends on temperature only.

15. Which one is the correct unit for entropy?
(a) KJ mol (b)JK mol
(c)JK mol^-1 (d) KJ mol^-1

16. An isochoric process takes place at constant
(a) temperature (b) pressure
(c) volume (d) concentration

17. Enthalpy of combustion of carbon to carbon dioxide is – 393.5 J mol^{-1   .}Calculate the heat released upon formation of 35.2 g of C0₂ from carbon and oxygen gas.