(a) What are the conditions when maximum and minimum boiling azeotropes are formed? Prove that for a closed multi-component system, in equilibrium, chemical potential of a component in all phases is the same.

(b) The molar volume of a binary liquid mixture at \(T\) and \(P\) is given by \[ V=120 x_{1}+70 x_{2}+\left(15 x_{1}+8 x_{2}\right) x_{1} x_{2} \]
Find the expression for the partial molar volume of species 1 and 2. Check whether the expression satisfies Gibbs-Duhem equation.