$3.$Enthalpy of mixing data for binary mixtures of water $(1)$ and toluene $(2)$ has been fit to the following

equation.

$2$

$1222(/)4022$ mixture $$H J mol $$ x x $$ x $$ x

At $20$ oC$,$ the activity coefficient of water $(\backslash$gamma $1)$ in $60\%$ water and $40\%$ toluene mixture is $1\mathrm{.}76.$

Estimate the activity coefficients of water and toluene at $60$oC$.$ Assume that the enthalpy does not

change with the temperature.