In the presence of excess oxygen,methane gas burns in a constant-pressure system to yield carbon dioxide and water: CH₄(g) + 2 O₂(g) → CO₂(g) + 2 H₂O(l) ΔH = -890.0 kJ
Calculate the value of q (kJ) in this exothermic reaction when 1.10 g of methane is combusted at constant pressure.

Question

Quizplus · Accepted Answer

First, we need to calculate the amount of heat released for the combustion of 1.10 g of methane.

1.10 g CH4 x (1 mol CH4/ 16.04 g CH4) x (-890.0 kJ/1 mol CH4) = -61.2 kJ

Note the negative sign indicates that the reaction is exothermic and releases heat. Therefore, the correct answer is (A) -61.2 kJ.

In the Presence of Excess Oxygen,methane Gas Burns in a Constant-Pressure