Question

Propane (C H ) reacts with elemental oxygen gas to produce carbon dioxide while giving off 2,220 kJ of energy. Is
this process endothermic or exothermic?

Answer 1

Explanation:

Write the thermochemical equation for the reaction of PCl3(g) with Cl2(g) to make PCl5(g), which has an enthalpy change of −88 kJ.

Solution

The thermochemical equation is

PCl3(g) + Cl2(g) → PCl5(g) ΔH = −88 kJ

Test Yourself

Write the thermochemical equation for the reaction of N2(g) with O2(g) to make 2NO(g), which has an enthalpy change of 181 kJ.

Answer

N2(g) + O2(g) → 2 NO(g) ΔH = 181 kJ