| The enthalpy changes for the following processes are listed below : |
| \[C{{l}_{2}}(g)\xrightarrow{{}}2Cl(g),242.3kJ\,mo{{l}^{-\,1}}\] |
| \[{{I}_{2}}(g)\xrightarrow{{}}2I(g),151.0\,kJ\,mo{{l}^{-\,1}}\] |
| \[ICl\,(g)\xrightarrow{{}}I\,(g)+Cl(g),211.3\,kJ\,mo{{l}^{-\,1}}\] |
| \[{{I}_{2}}(s)\xrightarrow{{}}{{I}_{2}}(g)62.76\,kJ\,mo{{l}^{-\,1}}\] |
| Given that the standard states for iodine and chlorine are \[{{I}_{2}}(s)\] and \[C{{l}_{2}}\,(g),\] the standard enthalpy for the formation of \[ICl\left( g \right)\] is |
A) \[-14.6\,kJ\,mo{{l}^{-\,1}}\]
B) \[-16.8\,kJ\,mo{{l}^{-\,1}}\]
C) \[+16.8\,kJ\,mo{{l}^{-\,1}}\]
D) \[+244.8\,kJ\,mo{{l}^{-\,1}}\]
Correct Answer: C
Solution :
| \[\frac{1}{2}{{I}_{2}}(s)+\frac{1}{2}C{{l}_{2}}(g)\xrightarrow{{}}ICl(g)\] |
| \[\Delta H=\left[ \frac{1}{2}\Delta {{H}_{s\to g}}+\frac{1}{2}\Delta {{H}_{\text{diss}}}(C{{l}_{2}}) \right.\]\[\left. +\frac{1}{2}\Delta {{H}_{diss}}({{I}_{2}})\, \right]-\Delta {{H}_{ICl}}\] |
| \[\left( \frac{1}{2}\times 62.76+\frac{1}{2}\times 242.3+\frac{1}{2}\times 151.0 \right)-211.3\] |
| \[=228.03-211.3\] |
| \[\Delta H=16.73\approx 16.8kJ\,mo{{l}^{-\,1}}.\] |
You need to login to perform this action.
You will be redirected in
3 sec
