The specific rate constant of a first-order reaction depends on .......

Which graph shows zero activation energy?

For the reaction $A_2 + B_2 \rightleftharpoons 2AB$,the activation energies for the forward and backward reactions are $180 \, kJ \, mol^{-1}$ and $200 \, kJ \, mol^{-1}$ respectively. In the presence of a catalyst,the activation energy for both (forward and backward) reactions decreases by $100 \, kJ \, mol^{-1}$. What will be the enthalpy change $(\Delta H)$ for the reaction $(A_2 + B_2 \rightarrow 2AB)$ in the presence of a catalyst in $kJ \, mol^{-1}$?

For the reaction $A_2 + B_2 \rightleftharpoons 2 AB$,the activation energies $(E_a)$ for the forward and backward reactions are $180 \ kJ \ mol^{-1}$ and $200 \ kJ \ mol^{-1}$ respectively. If a catalyst lowers the $E_a$ for both reactions by $100 \ kJ \ mol^{-1}$,which of the following statements is correct?

$A$ 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?