- 1(current)
Q. No.For the reaction:
N₂(g) + 3H₂(g) → 2NH₃(g) ; ΔᵣH° = –92.4 kJ mol⁻¹
What is the standard enthalpy of formation (ΔfH°) of NH₃(g)?
| 1. | -92.4 J (mol)-1 | 2. | -46.2 kJ (mol)-1 |
| 3. | +46.2 J (mol)-1 | 4. | +92.4 kJ (mol)-1 |
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Give 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
Enthalpy for the following reaction will be:
2. -243.6 kJ mol-1
3. -120.0 kJ mol-1
4. 553.0 kJ mol-1
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(298K) of methanol is given by the chemical equation:
1. \(\mathrm{C}(\text { diamond })+\frac{1}{2} \mathrm{O}_{2(\mathrm{~g})}+2 \mathrm{H}_{2(\mathrm{~g})} \rightarrow \mathrm{CH}_3 \mathrm{OH}_{(\mathrm{l})}\)
2. \(\mathrm{CH}_{4(\mathrm{~g})}+\frac{1}{2} \mathrm{O}_{2(\mathrm{~g})} \rightarrow \mathrm{CH}_3 \mathrm{OH}_{(\mathrm{g})}\)
3. \(\mathrm{CO}_{(\mathrm{g})}+2 \mathrm{H}_{2(\mathrm{~g})} \rightarrow \mathrm{CH}_3 \mathrm{OH}_{(\mathrm{l})}\)
4. \(\mathrm{C}(\text { graphite })+\frac{1}{2} \mathrm{O}_{2(\mathrm{~g})}+2 \mathrm{H}_{2(\mathrm{~g})} \rightarrow \mathrm{CH}_3 \mathrm{OH}_{(\mathrm{l})}\)
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The enthalpy of formation of are –110 kJ , – 393 kJ , 81 kJ and 9.7 kJ \(\text{mol}^{- 1}\) respectively. The value of \(\left(\Delta\right)_{r} H\) for the following reaction would be:
\(\mathrm{N_{2} O_{4 \left(g\right)} + 3 CO{\left(g\right)} \rightarrow N_{2} O_{\left(g\right)} + 3CO_{2 \left(g\right)}}\)
| 1. | \(- 777 . 7\) \(kJ\) \(\text{mol}^{- 1}\) | 2. | \(\) \(+ 777 . 7\) \(kJ\) \(\text{mol}^{- 1}\) |
| 3. | \(\) \(+ 824 . 9\) \(kJ\) \(\text{mol}^{- 1}\) | 4. | \(-\) \(345 . 4\) \(kJ\) \(\text{mol}^{- 1}\) |
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Which of the following is not an endothermic reaction?
1. Combustion of methane
2. Decomposition of water
3. Dehydrogenation of ethane or ethylene
4. Conversion of graphite to diamond
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When 4 g of iron is burnt in oxygen to form ferric oxide at constant pressure, 29.28 kJ of heat is evolved. Calculate the enthalpy of formation of ferric oxide.
(At. mass of Fe = 56) ?
1. 81.98 kJ
2. 819.8 kJ
3. 40.99 kJ
4. +819.8 kJ
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The standard enthalpy of the formation of CH3OH(l) from the following data is:
| \(\small{\mathrm{CH}_3 \mathrm{OH}_{(l)}+\frac{3}{2} \mathrm{O}_2(\mathrm{g}) \rightarrow \mathrm{CO}_2(\mathrm{g})+2 \mathrm{H}_2 \mathrm{O}_{(l)} \text {; }}\) \( \Delta_{\mathrm{r}} \mathrm{H}^{\circ}=-726 \mathrm{~kJ} \mathrm{~mol}{ }^{-1}\) |
| \(\small{\mathrm{C}(\mathrm{s})+\mathrm{O}_2(\mathrm{g}) \rightarrow \mathrm{CO}_2(\mathrm{g}) \text {; } }\) \(\Delta_{\mathrm{c}} \mathrm{H}^{\circ}=-393 \mathrm{~kJ} \mathrm{~mol}{ }^{-1}\) |
| \(\small{\mathrm{H}_{2(\mathrm{g})}+\frac{1}{2} \mathrm{O}_{2(\mathrm{g})} \rightarrow \mathrm{H}_2 \mathrm{O}_{(l)} \text {; } } \) \(\Delta_{\mathrm{f}} \mathrm{H}^{\circ}=-286 \mathrm{~kJ} \mathrm{~mol}^{-1}\) |
| 1. | −239 kJ mol−1 | 2. | +239 kJ mol−1 |
| 3. | −47 kJ mol−1 | 4. | +47 kJ mol−1 |
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- 1(current)
Q. No.
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