Explanation

(a)
The Arrhenius equation can be written as
$\log{k = \log{A - \frac{E_{a}}{2.303\ RT}}}$
On comparing this equation with standard equation of straight line
$y = mx + c,$ we get,
$y = \log k$
$x = \frac{1}{T}$
$m = - \frac{E_{a}}{2.303R}$
$c = \log A$
Hence, on plotting graph between $\log k(y - axis)and\frac{l}{T}\$($x$-axis), we get a line with slope equal to
$m = - \frac{E_{a}}{2.303\ R}$