Equal $1-$cm$2$ areas of metals P and Q are immersed together in sulfuric acid of unit H$+$

activity. $($a$)$ Determine corrosion potential and corrosion rate of each when they are

uncoupled, $($b$)$ When P and Q are electrically coupled, determine the potential and current

passing in the galvanic couple $($c$)$ Determine the corrosion rates for P and Q when the two

are galvanically coupled, $($d$)$ which metal is cathodically protected upon coupling and $($e$)$

On which metal is hydrogen evolution rate increased upon galvanic coupling? Use a

labeled graph paper.

Exchange current density for hydrogen evolution on P: $10-6$ A$/$cm$2$

Exchange current density for hydrogen evolution on Q: $10-5$ A$/$cm$2$

Exchange current density for metal dissolution on P: $3$ x $10-7$ A$/$cm$2$

Exchange current density for metal dissolution on Q: $2$ x $10-6$ A$/$cm$2$

Reversible potentials for anodic dissolution for P: $-0\mathrm{.}500$ V

Reversible potentials for anodic dissolution for Q: $-0\mathrm{.}600$ V

All Tafel constants are $0\mathrm{.}1$ V$/$dec