Ethane(a minor constituent of natural gas) burns in oxygen to form carbon dioxide and water. How many moles of oxygen are needed to react with one moles of ethane?

Answer 1

C2H6 + 7/2O2 => 2CO2 + 3HOH
moles O2 consumed permole C2H6 = 7/2 mole = 3.5 moles O2 per mole C2H6.