Answer: 13
Step-by-step explanation:
C4H10 + 02 → CO2 + H2O
To balance the above equation, put 2 in front of C4H10, 13 in front of O2, 8 in front CO2 and 10 in front of H2O i.e
2C4H10 + 1302 → 8CO2 + 10H2O
From the balanced equation, the coefficient of O2 is 13