Share
Explore BrainMass

Value of freezing point and Gibbs energy of mixture

1. If the vapor pressures of the two components in a binary solution are grven by
P1 = x1*P1*e^(u(x2^2))/RT and P2 = x2*P2*e^(u(x1^2))/RT
Show that,
Del(mix)*G/u = Del(mix)*G/(n1+n2)u = (RT/u) * (x1 ln(x1) * x2ln(x2))*x1x2
Del(mix)*S/R = Del(mix)*S/(n1+n2)R= -(x1 ln(x1) * x2ln(x2))
Del(mix)*H/u = Del(mix)*H/(n1+n2) = x1x2

A solution that satisfies these equations is called a regular solution. A statistical thermodynamic model of binary solutions shows that u is proportional to 2E12 - E11 -E22 ,where, Eij is the interaction energy between molecules of components i and j. Note-that u = 0 if E12 = (E11+ E22)/2, which means that energetically, moiecules of components 1 and 2 *like" the opposite molecules as well as their own.

2. Calculate the value of the freezing point depression constant for nitro-benzene, whose freezing point is 57 degree centigrade and whose enthalpy of fusion is 11.59 kJ/mol

(SEE QUESTIONS IN PROPER FORMAT FROM ATTACHED FILE "chem1.pdf")

Attachments

Solution Preview

Please see the attached MS Word document for the full solution to the questions asked. ...

Solution Summary

Step-by-step solutions of both problems is explained. The first problem is statement proven for Gibbs energy of mixture(binary solution) using A statistical thermodynamic model. The second problem is calculation of Value of freezing point for nitro-benzene.

$2.19