Apply Arrhenius equation
\(\log \,\frac{{{K_2}}}{{{K_1}}}\, = \,\frac{{{E_a}}}{{2.303\,R}}\left( {\frac{1}{{600}} - \frac{1}{{800}}} \right)\)
\(\log \,\frac{1}{{2.5 \times {{10}^{ - 4}}}}\, = \,\frac{{{E_a}}}{{2.303 \times 8.31}}\,\left( {\frac{{200}}{{600 \times 800}}} \right)\)
\(\therefore \,\,{E_a}\, \approx \,166\,\,kJ\,/\,mol\)
$1$. $[A]$ $0.012$, $[B]$ $0.0351\rightarrow $ પ્રારંભિક દર $ = 0.10$
$2$. $[A]$ $0.024$, $[B]$ $0.070\rightarrow $ પ્રારંભિક દર $= 1.6$
$3$. $[A]$ $0.024$, $[B]$ $0.035\rightarrow $ પ્રારંભિક દર $ = 0.20$
$4$. $[A]$ $0.012$ , $[B]$ $0.070\rightarrow $ પ્રારંભિક દર $ = 0.80$
(આપેલ છે: $\left. R =8.314\, J\, mol ^{-1} K ^{-1}\right)$