GKFix MCQ Question

In the equilibrium expression for 2Cu(NO₃)₂(s) ⇌ 2CuO(s) + 4NO₂(g) + O₂(g), why are solids not included in Kc?

• A. They do not participate in the reaction
• B. Their masses are too large
• C. Their concentrations remain constant
• D. They react too slowly