Please answer both Q a$)$ and Q b$)!$

$($a$)$ One end of a copper wire is immersed in an electrolyte of $0\mathrm{.}03MC{u}^{2+}$ ions and the

other in one of $0\mathrm{.}002MC{u}^{2+}$ ions, with the two electrolytes being separated by a

porous wall.

$($i$)$ Which end of the wire will corrode?

$($ii$)$ What will be the potential difference between the two ends of the wire when

it is just immersed in the electrolytes?

The standard electrode potential $E$ for copper $(Cu=C{u}^{2+}+2e^{-})$is $+0\mathrm{.}337$ Volts.

$($b$)$ At the surface of a steel bar there is one carbon atom per $40$ unit cells of iron. At $2mm$

below the surface, there is one carbon atom per $50$ unit cells. The diffusivity at $1000C$

is $3{10}^{-11}\frac{m^2}{s}.$ The structure at $1000C$ is face centred cubic $(a_0=0\mathrm{.}365(nm)).$ How

many carbon atoms diffuse through each unit cell per minute?