A balloon filled with $0\mathrm{.}0125$ mol of Helium at $20\mathrm{.}0C.$ The balloon weighted down and submerged $300$ m below the water's surface. The balloon has an initial volume $300$ mL at the water's surface.

a$.$ Solve for the pressure on the balloon at $30\mathrm{.}0$ m $($ans: $395\mathrm{.}3$ kPa $)$

b$.$ Solve for the new volume of the balloon if the temperature of the Helium is constant. $($ans $76\mathrm{.}9$ mL $)$

c$.$ How much work is done by the water to compress the gas? $($ans: $41\mathrm{.}4$ J $)$