Question

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

Answer 1

Answer:

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