Select all that apply. which two of the following equations represent an exothermic reaction? nh3(g) + 12.0 kcal → ½n2(g) + 3/2h2(g) c(graphite) → c(diamond), δh = -0.45 kcal/mole c c + 2s → cs2, δh = 27,550 cal ch4 + 2o2 → co2 + 2h2o + 212,800 cal 2h2 o → 2h2 + o2, δh = +58 kcal/mole h2o

C(graphite) → C(diamond), ΔH = -0.45

CH4 + 2O2 → CO2 + 2H2O + 212,800 cal

Explanation:

NH3(g) + 12.0 kcal → ½N2(g) + 3/2H2(g) in this reaction we see that energy is added to the reactants so this is an endorthermic process. It takes in energy

C(graphite) → C(diamond), ΔH = -0.45 kcal/mole The change in enthalpy for this reaction is listed and it is negative, telling us that this is an exothermic reaction.

C + 2S → CS2, ΔH = 27,550 cal  The change of enthalpy for this reaction is listed and it is positive which tells us that the reaction is endothermic reaction

CH4 + 2O2 → CO2 + 2H2O + 212,800 cal In this reaction, the energy is part of the equation on the products side. It is given out. this tells us that the reaction is exothermic

2H2 O → 2H2 + O2, ΔH = +58 kcal/mole H2O In this reaction, the energy is part of the equation on the products side. It is given out. this tells us that the reaction is exothermic

iron and sleel

make siroeel