GKFix MCQ Question

Which of the following reactions is an example of a homogeneous equilibrium?

• A. CaCO3(s) ⇌ CaO(s) + CO2(g)
• B. N2(g) + 3H2(g) ⇌ 2NH3(g)
• C. Fe(s) + Cu^2+(aq) ⇌ Fe^2+(aq) + Cu(s)
• D. AgNO3(aq) + NaCl(aq) ⇌ AgCl(s) + NaNO3(aq)