When the temperature changes from $20\,^oC$ to $50\,^oC$,the rate of reaction becomes three times. The activation energy $(E_a)$ for the reaction is $.... \, kJ \, mol^{-1}$ $(R = 8.314 \, J \, K^{-1} \, mol^{-1})$.

Catalysts are used to increase the rate of a chemical reaction. Because it

An exothermic reaction $X \rightarrow Y$ has an activation energy of $30 \ kJ \ mol^{-1}$. If the energy change $\Delta E$ during the reaction is $-20 \ kJ \ mol^{-1}$,then the activation energy for the reverse reaction in $kJ \ mol^{-1}$ is $...$.

For a chemical reaction $A \rightarrow B$,the activation energy in the forward direction is $E_a$. Then the activation energy in the reverse direction is.........

For a reaction,the threshold energy is $75 \ kJ/mol$. If the internal energy of the reactants is $20 \ kJ/mol$,the activation energy (in $kJ/mol$) is

Which of the following statements is true for a catalyst?