Energy of activation of a reactant is reduced by

For an exothermic reaction $A \rightarrow B$,the activation energy of $A$ is $17 \, kJ/mol$. The heat of reaction is $40 \, kJ$. Calculate the activation energy for the reverse reaction $B \rightarrow A$.

The activation energy for a reaction which doubles the rate when the temperature is raised from $298 \ K$ to $308 \ K$ is ........... $kJ \ mol^{-1}$

For a first-order gaseous reaction,a plot of $\log \, k$ versus $1/T$ gives a straight line with a slope of $-8000$. Calculate the activation energy $(E_a)$ of the reaction in $cal$.

The specific rate constant of a $1^{st}$ order reaction depends on the

Fill in the blank :
$1.$ In collision theory the molecules are hard .........
$2.$ In a reality the molecules are hard ..........
$3.$ Collision take place with .......... species.