(A) Given the reaction 2 CO(g) + O₂(g) ⇌ 2 CO₂(g), what is the effect of adding O₂(g) to a constant-volume equilibrium mixture?

(B) Calcination of limestone (decomposition by heating), CaCO₃(s) ⇌ CaO(s) + CO₂(g), is the commercial source of quicklime, CaO(s). After this equilibrium has been established in a constant temperature, constant-volume container, what is the effect on the equilibrium amounts of materials caused by adding some 

(a) CaO(s); 

(b) CO₂(g); 

(c) CaCO₃(s)?