Answer to Question #207762 in Physical Chemistry for pesky

Question

define Gibb's rule and explain the relationship between Gibb's Free energy and the feasibility of reactions

Answer 1

The Gibbs phase rule p+n=c+1 gives the relationship between the number of phases p and components c in a given alloy under equilibrium conditions at constant pressure, where n is the number of thermodynamic degrees of freedom in the system.

Whether or not a reaction (or other physical change) is feasible depends on the sign of ΔG. If ΔG is positive, then the reaction isn't feasible - it can't happen. For a reaction to be feasible, ΔG has to be negative.