Chemistry Gibbs Free Energy Solution: Given the thermodynamic data below, calculate the ...

🤓 Based on our data, we think this question is relevant for Professor Daykin's class at NCSU.

# Solution: Given the thermodynamic data below, calculate the value of the equilibrium constant for the reaction shown at 25.0º C. H2 (g) + CO2 (g) ⇌ CO (g) + H2O (g)Δ Hº = 41.15 kJΔ Sº = 42.35 J/K

###### Problem

Given the thermodynamic data below, calculate the value of the equilibrium constant for the reaction shown at 25.0º C.

H2 (g) + CO2 (g) ⇌ CO (g) + H2O (g)

Δ Hº = 41.15 kJ
Δ Sº = 42.35 J/K

###### Solution

We’re being asked to determine the equilibrium constant (K) at 25 ˚C for the given reaction:

H2(g) + CO2(g)  CO(g) + H2O(g)

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:

ΔH˚rxn = 41.15 kJ

ΔS˚rxn = 42.35 J/K

For this problem, we need to do the following steps:

Step 1: Use ΔH˚rxn and ΔS˚rxn to calculate for ΔG˚rxn.

Step 2: Calculate for K.

View Complete Written Solution