Water hydrazine system forms an azeotrope containing $58\mathrm{.}5\%($mol$)$ hydrazine

at $393$ K and $101\mathrm{.}3$ KPa. Calculate the equilibrium vapour composition for a

solution containing $20\%($mol$)$ hydrazine. The relative volatility of water with

reference to hydrazine is $1\mathrm{.}6$ may be assumed to remain constant in the

temperature range involved. The vapour pressure of hydrazine at $393$ K is

$124\mathrm{.}76$ kPa.