Final answer:
To find the energy absorption for 8.71 mol of NH3, we calculate the energy per mole (11.0 kcal) and multiply by the number of moles (8.71), which equals 95.81 kcal. This does not match any of the given answer options.
Step-by-step explanation:
The question is asking how much energy is absorbed when 8.71 mol of ammonia (NH3) decomposes into hydrogen and nitrogen given that the decomposition of 2 mol of NH3 absorbs 22.0 kcal of energy. The balanced chemical equation is 2 NH3(g) → 3 H2(g) + N2(g) ΔH = 22.0 kcal. To find out how much energy is absorbed when 8.71 mol of NH3 reacts, we first need to determine the amount of energy absorbed per mole of NH3, and then multiply that by the number of moles reacting.
The given reaction shows that 22.0 kcal of energy is absorbed for every 2 moles of NH3, which means that for 1 mole of NH3, the energy absorbed is 22.0 kcal / 2 = 11.0 kcal. Therefore, for 8.71 moles, the total energy absorbed will be 8.71 mol * 11.0 kcal/mol = 95.81 kcal. However, since this number does not match any of the given options (a) 12.3 kcal, (b) 31.8 kcal, (c) 44.0 kcal, or (d) 69.6 kcal, a recalculation or clarification of the given answer choices may be necessary, as the calculated energy does not fit the provided options.