An equimolar mixture of nitrogen and acetylene enters a steady$-$flow reactor at $25\backslash$deg C and atmospheric pressure. The only reaction occurring is: N$2($g$)+$ C$2$ H$2($g$)->2$HCN $($g$).$ The product gases leave the reactor at $600\backslash$deg C and contain $24\mathrm{.}2$ mol$-\%$ HCN$.$ How much heat is supplied to the reactor per mole of product gas?