Using the equations below

Cu(s) + ¹/₂O₂(g) → CuO(s) ∆H = –156 kJ

2Cu(s) + O₂(g) → Cu₂O(s) ∆H = –170 kJ

what is the value of ∆H (in kJ) for the following reaction?

2CuO(s) → Cu₂O(s) + ¹/₂O₂(g)

Consider the following equations.

Mg(s) + O₂(g) → MgO(s) ∆H = –602 kJ

H₂(g) + O₂(g) → H₂O(g) ∆H = –242 kJ

What is the ∆H value (in kJ) for the following reaction?

MgO(s) + H₂(g₎ → Mg(s) + H₂O(g)

The following equations show the oxidation of carbon and carbon monoxide to carbon dioxide.

C(s) +O₂(g) → CO₂(g) ΔH = –x kJ mol^–1

CO(g) + O₂(g) → CO₂(g) ΔH = –y kJ mol^–1

What is the enthalpy change, in kJ mol^–1, for the oxidation of carbon to carbon monoxide?

C(s) + O₂(g) → CO(g)

The standard enthalpy change of formation values of two oxides of phosphorus are:

P₄(s) + 3O₂(g₎ → P₄O₆(s) ΔH_f = –1600 kJ mol^–1

P₄(s) + 5O₂(g) → P₄O₁₀(s) ΔH_f = –3000 kJ mol^–1

What is the enthalpy change, in kJ mol^–1, for the reaction below?

P₄O_6(s) + 2O₂(g) → P₄O₁₀(s)

A chemical reaction that requires energy is a(n)

If N₂ (g) + 2O₂ (g) $$\longrightarrow$$   2NO₂(g) has a $$\Delta H_{rxn\ }$$  = 68, then what is the $$\Delta H_{rxn}$$  if you reverse the reaction?