JEE MAIN - Chemistry (2005 - No. 2)
Consider an endothermic reaction, X $$\to$$ Y with the activation energies Eb and Ef
for the backward and forward reactions, respectively. In general :
Eb < Ef
Eb > Ef
Eb = Ef
There is no definite relation between Eb and Ef
Објашњење
Enthalpy of reaction $$\left( {\Delta H} \right) = {E_{{a_{\left( f \right)}}}} - {E_{{a_{\left( b \right)}}}}$$
for an endothermic reaction $$\Delta H = + ve$$
Hence for $$\Delta H$$ to be negative
$$\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,$$ $$\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,$$ $${E_{{a_{\left( b \right)}}}} < {E_{{a_{\left( f \right)}}}}$$
for an endothermic reaction $$\Delta H = + ve$$
Hence for $$\Delta H$$ to be negative
$$\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,$$ $$\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,$$ $${E_{{a_{\left( b \right)}}}} < {E_{{a_{\left( f \right)}}}}$$