How are the values of $E_a$ and $A$ obtained from the Arrhenius equation?

For the forward reaction $X \rightarrow Y$,the activation energy is $60 \ kJ \ mol^{-1}$ and $\Delta H = -20 \ kJ \ mol^{-1}$. What is the activation energy for the reverse reaction $Y \rightarrow X$ in $kJ \ mol^{-1}$?

Which of the following would give a linear plot?
($k$ is the rate constant of an elementary reaction and $T$ is temperature in absolute scale)

For the reaction $A + B \rightarrow C + D$,$\Delta H = -20 \ kJ \ mol^{-1}$. The activation energy for the forward reaction is $85 \ kJ \ mol^{-1}$. The activation energy for the reverse reaction is ......... $kJ \ mol^{-1}$.

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

The rate constant,the activation energy and the Arrhenius parameter of a chemical reaction at $25\,^oC$ are $3.0 \times 10^{-4}\,s^{-1}$,$104.4\,kJ\,mol^{-1}$ and $6.0 \times 10^{14}\,s^{-1}$ respectively. The value of the rate constant as $T \to \infty$ is