In the Arrhenius equation,$k = A e^{-E_a/RT}$,the Arrhenius constant $A$ will be equal to the rate constant when

Activation energy of any reaction depends on

$A$ reaction has an activation energy of $209 \, kJ \, mol^{-1}$. The rate increases $10$-fold when the temperature is increased from $27^{\circ} C$ to $X^{\circ} C$. The temperature $X$ is closest to
[Gas constant,$R = 8.314 \, J \, mol^{-1} \, K^{-1}$ ]

Calculate the activation energy of a reaction,whose rate constant doubles on raising the temperature from $300 \ K$ to $600 \ K$.

At room temperature,the reaction between $NO$ and $O_2$ to form $NO_2$ is fast,whereas the reaction between $CO$ and $O_2$ is slow because:

For $N_2 + 3H_2 \rightarrow 2NH_3$,$\Delta H = -22 \ kcal$,and $E_a = 70 \ kcal$. Hence $E_a$ for $2NH_3 \rightarrow N_2 + 3H_2$ is $.....$ $kcal$.