Question

One kmol of CO₂ is heated at a constant pressure of 100 kPa to 3000 K. (a) Calculate the equilibrium composition of CO₂ and use the IGE system state TESTcalc to verify your answers. (b) Use the n-IG system state TESTcalc and calculate the Gibbs function of the mixture (1-x)CO₂ + xCO + (x/2)O₂ at 100 kPa, 3000 K for x varying from 0 to 1. Show that for x = 0.438, Gibbs function reaches a minimum.

Answer 1

2 CO2 1 CO-> 1.56061 CO 0.085 O 0.2377 O 1.4394 CO The equilibriumconstant for thereactionCO+CO can be expressed as CO CO, N CO cN 2 total judging from the values, theK pvalue for this reaction decreases astemperature increases. That is, theindicated reaction will be less complete at higher temperatures.Therefore, the number of moles of CO2will decrease and the number moles of CO and O2will increase as thetemperature increases The value of the exponent in this case isl-1-0.5--0.5, which is negative. Thus as the pressure increases, the term in thebrackets willdecrease. The value of K pdepends on temperature only, and therefore it willnot change with pressure.Thento keep theequation balanced, the number of moles of the products (CO2) must increase, and the number of moles of thereactants (CO, O2) must decrease.