Question

A) Consider the reaction
3 Fe₂O₃(s) + H₂(g) --> 2 Fe₃O₄(s) + H₂O(g)
Using the standard thermodynamic data in the tables linked above, calculate the equilibrium constant for this reaction at 298.15K.

B) Consider the reaction

CaCO₃(s)--->CaO(s) + CO₂(g)
Using the standard thermodynamic data in the tables linked above, calculate the equilibrium constant for this reaction at 298.15K.

Answer 1

3 Fe₂O₃(s) + H₂(g) --> 2 Fe₃O₄(s) + H₂O(g)

G of Fe3O4 = -1015.45 KJ/mol

H₂O = -228.58 KJ/mol

Reactants

G of Fe₂O₃ = -742.24 KJ/mol

G = G (products) - G (reactants)

G = 2 * -1015.45 - 228.58 + 3* 742.24 = -32.76 KJ/mol

Applying formula

R is gas constant 8.314 J / mol K

T is temperature 298.15 K from the statement

K = 549, 064.039

B) CaCO₃(s)--->CaO(s) + CO₂(g)

G products:

CaO = -603.5 KJ/mol

CO₂ = -394.38 KJ/mol

G reactants

CaCO₃ = -1128 KJ/mol

G = G products - G reactants

G = -603 + -394.38 - (-1128.2) = 130.2 KJ/mol

K = 1.59 x 10^-23