When ethane reacts with oxygen to form carbon dioxide and water. When 10 molecules of ethane react with 20 molecules of oxygen, what is the composition of the FINAL mixture?

1 answer

I would balance the equation:

C2H4+3O2 >> 2CO2 + 2H2O

So it looks to me as if you did not have enough oxygen, which means, only 2/3 of the ethane was consumed.

So you have an issue, as molecules only occur in whole number.

I see
4 molecules C2H4 ; six consumed
2 molecules O2 left; 18 consumed
CO2; six made
H2O; twelve made