This preview shows page 1. Sign up to view the full content.
Unformatted text preview: terms of the properties of the individual components, consider a mixture of four chemical components A, B, C, and D that exist in equilibrium at a specified temperature and pressure. Let the number of moles of the respective components be NA, NB, NC, and ND. Now consider a reaction that occurs to an infinitesimal extent during which differential amounts of A and B (reactants) are converted to C and D (products) while the temperature and the pressure remain constant (Fig. 165):
dN A A dN B B dN C C dN D D FIGURE 164 Criteria for chemical equilibrium for a fixed mass at a specified temperature and pressure. The equilibrium criterion (Eq. 164) requires that the change in the Gibbs function of the mixture during this process be equal to zero. That is,
1dG2 T,P a 1dG i 2 T,P g D dND a 1 g i dN i 2 T,P g B dNB 0
(165) REACTION CHAMBER T, P NA moles of A NB moles of B NC moles of C ND moles of D dNAA + dNBB dNCC + dNDD or
g C dNC g A dNA 0
(166) where the g's are the molar Gibbs functions (also called the chemical potentials) at the specified temperature and pressure and the dN's are the differential changes in the number of moles of the components. To find a relation between the dN's, we write the corresp...
View Full Document
This note was uploaded on 06/15/2009 for the course MAE 3311 taught by Professor Hajisheik during the Summer '08 term at UT Arlington.
- Summer '08