There’s a multiple choice question on entropy which asks ‘in which one of the following reactions is there a decrease in entropy?’
A. [Fe(H2O)6]³⁺ (aq)+3C2O4²⁻ (aq) -> [fe(C2O4)3]³ ⁻ (aq) + 6H20 (l)
B. [Cu(H2O)6]² ⁺ (aq) + EDTA⁴ ⁻ (aq) -> [Cu(EDTA)]² ⁻ (aq) + 6H2O (l)
C. [CoCl4]²⁻ (aq) + 6H2O(l) -> [Co(H2O)6]²⁺ (aq) + 4Cl⁻ (aq)
D. Na2CO3 (s) + 2H⁺ (aq) -> 2Na⁺ (aq) + CO2(g) + H2O(l)
I don’t understand why the answer is D and not C, I thought that D would have an increase in entropy because there are more moles in the products and it goes from s + aq -> aq + g + l, I thought the products would have a higher entropy than s + aq. Also C has more moles in reactants than products so surely there would be a decrease? I would really appreciate it if anyone could explain this to me
Thanks in advance