Enthalpy change for the reaction,
4H(g) 2H2(g) is -869.6 kJ
The dissociation energy of H-H bond is
1. -869.6 kJ
2. + 434.8 kJ
3. +217.4 kJ
4. -434.8 kJ
Given the following bond energies:
| H-H bond energy | 431.37 kJ mol-1 |
| C=C bond energy | 606.10 kJ mol-1 |
| C-C bond energy | 336.49 kJ mol-1 |
| C-H bond energy | 410.50 kJ mol-1 |
Based on the data given above, enthalpy change for the following reaction will be:
1. 1523.6 kJ mol-1
2. -243.6 kJ mol-1
3. -120.0 kJ mol-1
4. 553.0 kJ mol-1
The values of H and S for the given reaction are 170 kJ and 170 JK–1, respectively.
\(\mathrm{C} \text { (graphite) }+\mathrm{CO}_2(\mathrm{~g}) \rightarrow 2 \mathrm{CO}(\mathrm{g})\)
This reaction will be spontaneous at:
1. 710 K
2. 910 K
3. 1110 K
4. 510 K
Which of the following are not state functions?
(I) q + W (II) q
(III) W (IV) H-TS
1. (I) and (IV)
2. (II), (III) and (IV)
3. (I) , (II) and (III)
4. (II) and (III)
| \(\small\text{(i)}~ \text{H}^+(aq) + \text{OH}^-(aq) \rightarrow \text{H}_2\text{O}(l); \quad \Delta H = -x_1 \text{ kJ mol}^{-1}\) |
| \(\small\text{(ii)}~ \text{H}_2(g) + \frac{1}{2}\text{O}_2(g) \rightarrow \text{H}_2\text{O}(l); \quad \Delta H = -x_2 \text{ kJ mol}^{-1}\) |
| \(\small\text{(iii)}~ \text{CO}_2(g) + \text{H}_2(g) \rightarrow \text{CO}(g) + \text{H}_2\text{O}(l); \quad \Delta H = -x_3 \text{ kJ mol}^{-1}\) |
| \(\small(iv)~ \text C_ 2\text H_ 5 ( g ) + \frac{5} {2} \text O_ 2 ( g ) = 2 \text C\text O_ 2 ( g ) + \text H_ 2 \text O ( l )~; ∆ H = - x_ 4~ kJ mol^ {- 1} \) |
Choose the correct option:
1. -x2 kJ mol-1
2. +x3 kJ mol-1
3. -x4 kJ mol-1
4. -x1 kJ mol-1
Identify the correct statement for the change of Gibbs free energy for a system (Gsystem) at constant temperature and pressure:
| 1. | If Gsystem > 0, the process is spontaneous |
| 2. | If Gsystem = 0, the system has attained equilibrium |
| 3. | If Gsystem = 0, the system is still moving in a particular direction |
| 4. | If Gsystem < 0, the process is not spontaneous |
The enthalpy and entropy change for the reaction :
Br2 (l) + Cl2 (g) 2BrCl (g)
are 30 kJ mol-1 and 105 J K-1 mol-1 respectively.
The temperature at which the reaction will be in equilibrium is :
| 1. | 285.7 K | 2. | 273.4 K |
| 3. | 450.9 K | 4. | 300.1 K |
The enthalpy of combustion of H2, cyclohexene (C6H10) and cyclohexane (C6H12) are -241, -3800 and -3920 kJ per mol respectively. Heat of hydrogenation of cyclohexene is:
(a) -121 kJ per mol
(b) +121 kJ per mol
(c) +242 kJ per mol
(d) -242 kJ per mol
Consider the reactionat 300K
H2(9) + Cl2(9) →2HCI(g), ΔH° = — 185 KJ
If 3 mole of H2 completely react with 3 mol of Cl2 to form Cl, U° of the reaction will be
(1) Zero
(2) –185 KJ
(3) -555 KJ
(4) None
For a perfectly crystalline solid Cpm = aT3, where a is constant. If Cpm is 0.42 J/K–mol at 10 K, molar entropy at 10 K is
1. 0.42 J/K–mol
2. 0.14 J/K–mol
3. 4.2 J/K–mol
4. zero
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