The heat-of-mixing data of Featherstone and Dickinson [J. Chem. Thermodyn., 9, 75 (1977)] for the n-octanol + n-decane liquid mixture at atmospheric pressure is approximately fit by

with T in K and x₁ being the n-octanol mole fraction. 

a. Compute the difference between the partial molar and pure-component enthalpies of n-octanol and of n-decane at x₁ = 0.5 and T = 300 K. 

b. Compute the difference between the partial molar and pure-component heat capacities of n-octanol and of n-decane at x₁ = 0.5 and T = 300 K. 

c. An x₁ = 0.2 solution and an x₁ = 0.9 solution are to flow continuously into an isothermal mixer in the mole ratio 2:1 at 300 K. Will heat have to be added or removed to keep the temperature of the solution leaving the mixer at 300 K? What will be the heat flow per mole of solution leaving the mixer? 

Transcribed Image Text:

Amix H = 12 (A + B(x₁ - x₂)) where and A = -12 974 + 51.505T B +8782.8 - 34.129T = J/mol