Select all that apply.

Which of the following equilibria will shift to the left when the temperature is increased? [ΔH (kJ/mol) values are given in parentheses.]

(a) S + H2 ⇌ H2S ΔH (−20)


(b) C + H2O ⇌ CO + H2 ΔH (131)


(c) H2 + CO2 ⇌ H2O + CO ΔH (41)


(d) MgO + CO2 ⇌ MgCO3 ΔH (−117)


(e) 2CO + O2 ⇌ 2CO2 ΔH (−566)