Current Attempt in Progress

Compressed air can be pumped underground into huge caverns as a form of energy storage. The volume of a cavern is $5\mathrm{.}4{10}^5{m}^3,$ and the pressure of the air in it is $8\mathrm{.}3{10}^{6}Pa.$ Assume that air is a diatomic ideal gas whose internal energy $U$ is given by $U=\frac{5}{2}nRT.$ If one home uses $30\mathrm{.}0$ kW h of energy per day, how many homes could this internal energy serve for one day?