The heat necessary to melt I mole of ice at $693\mathrm{.}2$k freezing point is obtained at using a reversible carnot machine. The melting enthalpy of zinc and ice are $601\mathrm{9 }$&$\mathrm{ 7}273\frac{}{}$ j/ mole respectively. Calculate the amount of zinc necessary to mett I mole of ice, the work and the yield obtained from the machine.