Select all of the following equations that represent an exothermic reaction. C + 2S → CS 2, ΔH = 27,550 cal
NH 3(g) + 12.0 kcal → ½N 2(g) + 3/2 H 2(g)
CH 4 + 2O 2 → CO 2 + 2H 2O + 212,800 cal
2H 2O → 2H 2 + O 2, ΔH = +58 kcal
C (graphite) → C (diamond), ΔH = - 0.45 kcal

Exothermic reactions:

1) release heat to the surroundings

2) the change of enthalpy, AH, is negative: AH < 0

3) the temperature of the system increases

With that you can conclude about every
equation given:

I. NH3(g) + 12.0 kcal » Y2N2(g) + 3/2 H2(g):

IS NOT exothermic because heat in the side of the reactants means that heat is being used, not released.

II. C(graphite) > C(diamond), AH = - 0.45 kcal:

IS exothermic because AH is negative

III. C+ 2S * CS2, AH = 27,550 cal:

IS NOT exothermic because AH is positive

IV. CH4 + 202 = CO2 + 2H20 + 212,800 cal : IS exothermic because heat appears as a product of the reaction, which means that it is
released.

V. 2H20 * 2H2 + O2, AH = +58 kcal:

IS NOT exothermic because AH is positive.

- HOPE THIS HELPS

(BRAINLIEST WOULD BE MUCH APPRECIATED) :))