Question

How do I balance C2H6+O2---> CO2 +H2O

Answer 1

You just make the same number of C's, H's and O's on both sides.
So it would be 2 C2H6 + 7 O2 ---> 4 CO2 + 6 H2O

Answer 2

I understand that I need to make both sides balanced. But how do I get 2 C2H6 + 7O2 --> 4 CO2 + 6 H2O

Answer 3

I usually start with balancing the C's and H's and leave O's for last. So, the first step would be C2H6 + O2 -> 2CO2 + 3H2O. Now try to balance the O's. C2H6 + 7/2O2 -> 2CO2 + 3H2O. Now multiply the entire reaction by 2 to clear the fraction. 2C2H6 + 7O2 -> 4CO2 + 6H2O.