Question

Select all of the following reactions that are endothermic.

H2(g) + ½O2(g) → H2O(g), ΔH = -57.83 kcal/mole
½N2(g) + ½O2(g) → NO(g), ΔH = +21.6 kcal/mole
½N2(g) + O2(g) + 8.1 kcal → NO2(g)
½N2(g) + 3/2H2(g) → NH3(g) + 11.0 kcal/mole
NH3(g) → ½N2(g) + 3/2H2(g), ΔH = +11.0 kcal/mole