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 $.....$ $kcal$.

The rate of a chemical reaction doubles for every $10\,^{\circ}C$ rise in temperature. If the temperature is increased to $50\,^{\circ}C$ from $0\,^{\circ}C$,by how many times will the rate of reaction increase?

For a chemical reaction,if the temperature is increased from $25\,^{\circ}C$ to $55\,^{\circ}C$,the rate of reaction will change by a factor of (Assume $\mu = 3$).

The activation energy for a simple chemical reaction $A \to B$ is ${E_a}$ in the forward direction. The activation energy for the reverse reaction:

In a reaction,the rate constant $K_1$ is twice the rate constant $K_2$ of another reaction. Find the relationship between the activation energies $E_1$ and $E_2$ of the two reactions at the same temperature.

With an increase in temperature,the rate constant $k$: