Two similar reactions have the same rate constant at 25^ C , but at...

At room temperature i.e., $25^{\circ} \mathrm{C}$, two similar reactions have the same rate constant. But when this temperature increases to $10^{\circ} \mathrm{C}$ the rate constant becomes 2 to 3 times greater than other. This is happened because at higher temperature, activation energies of reacting molecules are different so that collisions be effective. Therefore, at different activation energies rate constant also become higher than initial one.