question_answer

A certain reaction proceeds in sequence of three elementary steps with rate constant \[{{K}_{1}},{{K}_{2}}\]and\[{{K}_{3}}\]. If \[{{K}_{obs}}={{\left[ \frac{{{K}_{1}}}{{{K}_{2}}} \right]}^{{}^{1}/{}_{2}}}{{K}_{3}}\] the observed \[{{E}_{a}}\]is:

A) \[\frac{1}{2}\left[ \frac{{{E}_{1}}}{{{E}_{2}}} \right]+{{E}_{3}}\]                  

B) \[\frac{{{E}_{3}}+{{E}_{1}}}{2}\]

C) \[\frac{1}{2}{{\left[ \frac{{{E}_{1}}}{{{E}_{2}}} \right]}^{{}^{1}/{}_{2}}}\]            

D) \[{{E}_{3}}+\frac{1}{2}[{{E}_{1}}-{{E}_{2}}]\]