Heterogeneous equilibria
Chemical Equilibrium · Chemistry
Study notes
CaCO₃(s) ⇌ CaO(s) + CO₂(g), K_p = 0.05 atm at some T. What happens if more CaCO₃ is added? Step 1: K_p = p(CO₂) — solids omitted. Step 2: Adding solid doesn't change p(CO₂) → Q still = K. Step 3: NO shift — as long as some of each solid is present. Step 4: But removing CO₂ (lowering p) → Q < K → more CaCO₃ decomposes. Solids are 'invisible' to equilibrium — only gases/aqueous count.