Final answer:
To calculate the heat generated from the combustion of ethane using 185 grams of oxygen, one must find the moles of oxygen and then use the stoichiometric relationship from the balanced chemical equation to determine the heat produced, which is approximately 1.18 x 10^3 kJ.
Step-by-step explanation:
The student's question revolves around the combustion of ethane and the amount of heat produced when a given mass of oxygen is consumed. Given that the balanced equation for the combustion of ethane is 2C2H6 + 7O2 → 4CO2 + 6H2O + 2.86 x 103 kJ, if we have 185 grams of oxygen gas (O2), we'll first need to calculate the number of moles of oxygen.
Moles of O2 = mass (g) / molar mass (g/mol) = 185 g / 32 g/mol = 5.78125 moles. Then, we'll look at the stoichiometric relationship between O2 and heat energy, which in the balanced equation is 7 moles of O2 producing 2.86 x 103 kJ. Thus, the heat generated from 5.78125 moles of O2 can be calculated by setting up a proportion:
Heat generated = (2.86 x 103 kJ / 7 moles O2) x 5.78125 moles O2 = 1.18 x 103 kJ (rounded to two significant figures).
Therefore, when 185 grams of oxygen gas are consumed, approximately 1.18 x 103 kJ of heat can be generated.