Among the following graphs showing the variation of rate constant $(k)$ with temperature $(T)$ for a reaction,the one that exhibits Arrhenius behaviour over the entire temperature range is:

What is the activation energy for the reverse of this reaction?
$N_2O_{4(g)} \to 2NO_{2(g)}$
Data for the given reaction is:
$\Delta H = +54 \ kJ$ and $E_a = +57.2 \ kJ$
Answer in $kJ$.

$A$ chemical reaction was carried out at $300 \, K$ and $280 \, K$. The rate constants were found to be $K_1$ and $K_2$ respectively. The energy of activation is $1.157 \times 10^4 \, cal \, mol^{-1}$ and $R = 1.987 \, cal \, K^{-1} \, mol^{-1}$. Then:

What is the role of a catalyst in a chemical reaction?

At a constant temperature,the activation energy of a reaction is found to be $2.303 \, RT \, J \, mol^{-1}$. The ratio of the rate constant to the Arrhenius constant will be $......$.

How fast is the reaction at $25\, ^\circ C$ as compared to $0\, ^\circ C$,if the activation energy is $65\, kJ/mol$?