Unformatted text preview: onding stoichiometric (theoretical) reaction FIGURE 165 An infinitesimal reaction in a chamber at constant temperature and pressure. nA A nB B nC C nD D (167) where the n's are the stoichiometric coefficients, which are evaluated easily once the reaction is specified. The stoichiometric reaction plays an important role in the determination of the equilibrium composition of the reacting 796 | Thermodynamics
mixtures because the changes in the number of moles of the components are proportional to the stoichiometric coefficients (Fig. 166). That is,
H2 2H 0.1H2 0.2H 0.01H2 0.02H 0.001H2 0.002H nH = 1
2 dN A dN B enA enB dN C dN D enC enD (168) nH = 2 where e is the proportionality constant and represents the extent of a reaction. A minus sign is added to the first two terms because the number of moles of the reactants A and B decreases as the reaction progresses. For example, if the reactants are C2H6 and O2 and the products are CO2 and H2O, the reaction of 1 mmol (10 6 mol) of C2H6 results in a 2-mmol increase in CO2, a 3-mmol increase in H2O, and a 3.5-mmol decrease in O2 in accordance with the stoichiometric equation
C2H6 3.5O2 S...
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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