1. From the balanced equation given above, the ratio of the number of moles of the hydrocarbon and oxygen is equal to 2/7. Given that there are 2 moles of oxygen,
moles hydrocarbon = (2 moles O2)(2 moles HC / 7 moles oxygen)
Simplifying,
moles HC = 4/7 or 0.57 moles HC
Answer: 0.57 moles HC
2. The calculation for the mass of water is shown below with the dimensional analysis and conversion factors,
(30 g C2H6)1 mole C2H6/30 g C2H6)(6 molesH2O/2 moles C2H6)(18 g H2O/1 mole C2H6)
Simplifying,
mass = 54 grams of water