Consider a mixture of water and salt with a low salt concentration. Use the ideal mixture law (8.68) to evaluate the chemical potential of water in the salt solution. Recall that according to relation (8.51), for any substance A in any given phase, μ_A (T) = h_A − T s_A. Assume that near the boiling temperature T₀ of pure water, the molar enthalpy h_A and the molar entropy s_A of the liquid and vapour phases do not depend on temperature. Determine the boiling temperature variation T − T₀ as a function of salt concentration c_A.