A) is always double of \[{{E}_{a}}\]
B) is negative of \[{{E}_{a}}\]
C) is always less than \[{{E}_{a}}\]
D) can be less than or more than \[{{E}_{a}}\]
Correct Answer: D
Solution :
[d] The activation energy of reverse reaction will depend upon whether the forward reaction is exothermic or endothermic. As \[\Delta H={{E}_{a}}\] (forward reaction)-\[{{E}_{a}}\](backward reaction) For exothermic reaction \[\Delta H=-ve\] \[\therefore -\Delta H={{E}_{a}}(f)-{{E}_{a}}(b)\] Or \[{{E}_{a}}\left( f \right)={{E}_{a}}\left( b \right)-\Delta H\] \[\therefore {{E}_{a}}\left( f \right)<{{E}_{a}}\left( b \right).\] for endothermic reaction \[\Delta H=+ve\] \[\therefore \Delta H={{E}_{a}}(f)-{{E}_{a}}(b)\,or\,{{E}_{a}}(f)=\Delta H+{{E}_{a}}(b)\] \[\therefore {{E}_{a}}(f)>{{E}_{a}}(b).\]You need to login to perform this action.
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