Given
\(\begin{aligned} &\mathrm{{C}_{{(graphite) }}+{O}_{2}({~g})} → \mathrm{{CO}_{2}({~g})} \\ &\mathrm{\Delta_{r} {H}^{\circ}=-393.5 {~kJ} {~mol}^{-1}} \\ &\mathrm{H_{2}(g) + \frac{1}{2} {O}_{2}({~g})} → \mathrm{{H}_{2} {O}({l})} \\ &\mathrm{\Delta_{r} {H}^{\circ}=-285.8 {~kJ} {~mol}^{-1}} \\ &\mathrm{{CO}_{2}({~g})+2 {H}_{2} {O}({l})} → \mathrm{{CH}_{4}({~g})+2 {O}_{2}({~g})} \\ &\mathrm{\Delta_{r} {H}^{\circ}=+890.3 {~kJ} {~mol}^{-1}} \end{aligned}\)
Based on the above thermochemical equations, the value of ΔrH° at 298 K for the reaction
\(\mathrm{C_{(graphite)} + 2 H_{2} (g) → CH_{4} (g)}\) will be :
1. –74.8 kJ mol–1
2. –144.0 kJ mol–1
3. +74.8 kJ mol–1
4. +144.0 kJ mol–1
Consider the reaction:
ΔrH = –111 kJ
If N2O5(s) is formed instead of N2O5(g) in the above reaction, the rH value will be :
(Given: H of sublimation for N2O5 is 54 kJ mol–1)
1. +54 kJ
2. + 219 kJ
3. –219 kJ
4. –165 kJ
1. | - 610 kJ mol-1 | 2. | - 850 kJ mol-1 |
3. | +120 kJ mol-1 | 4. | +152 kJ mol-1 |
The enthalpy changes for the following processes are listed below :
Cl2 (g) → 2Cl(g), 242.3 kJ mol-1
I2 (g) → 2I (g), 151.0 kJ mol-1
ICI (g) → I(g) + Cl(g), 211.3 kJ mol-1
I2 (s) → I2 (g), 62.76 kJ mol-1
Given that the standard states for iodine and chlorine are I2 (s) and Cl2 (g), the standard enthalpy of formation of ICI (g) is :
1. -14.6 kJ mol-1
2. -20.8 kJ mol-1
3. +16.8 kJ mol-1
4. +244.8 kJ mol-1
The enthalpies of combustion of carbon and carbon monoxide are -393.5 and -283 kJ mol-1 respectively. The enthalpy of the formation of carbon monoxide per mole is:
1. 110.5 kJ
2. 676.5 kJ
3. -676.5 kJ
4. -110.5 kJ