Gibbs Free Energy Video Lessons

Concept

# Problem: Consider the decomposition of barium carbonate: BaCO3 (s) ⇄ BaO(s) + CO2 (g)Using data from Appendix C in the textbook, calculate the equilibrium pressure of CO2 at 1300 K .

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###### FREE Expert Solution

We’re being asked to determine the equilibrium pressure COat 1300 K for the given reaction:

BaCO3 (s)  BaO(s) + CO2 (g)

The K expression for this reaction is:

$\overline{){{\mathbf{K}}}_{{\mathbf{p}}}{\mathbf{=}}\frac{\mathbf{products}}{\mathbf{reactants}}{\mathbf{=}}{{\mathbf{P}}}_{{\mathbf{CO}}_{\mathbf{2}}}}$

*Note: Solids and liquids are not included in the equilibrium constant expression.

Recall that ΔG˚rxn and K are related to each other:

$\overline{){\mathbf{\Delta G}}{{\mathbf{°}}}_{{\mathbf{rxn}}}{\mathbf{=}}{\mathbf{-}}{\mathbf{RTlnK}}}$

We can use the following equation to solve for ΔG˚rxn:

$\overline{){\mathbf{\Delta G}}{{\mathbf{°}}}_{{\mathbf{rxn}}}{\mathbf{=}}{\mathbf{\Delta H}}{{\mathbf{°}}}_{{\mathbf{rxn}}}{\mathbf{-}}{\mathbf{T\Delta S}}{{\mathbf{°}}}_{{\mathbf{rxn}}}}$

We’re given the ΔH˚rxn and ΔS˚rxn of the reaction from the appendix:

ΔH˚rxn = -1213.0 kJ/mol

ΔS˚rxn = 112.1 J/mol•K

99% (84 ratings)
###### Problem Details

Consider the decomposition of barium carbonate: BaCO3 (s) ⇄ BaO(s) + CO2 (g)

Using data from Appendix C in the textbook, calculate the equilibrium pressure of CO2 at 1300 K .