Answer: option D. 6.5
Step-by-step explanation:
C4H10 + 02 → CO2 + H2O
To balance the the above equation, add 2 in front of C4H10, 13 in front of O2, 8 in front of CO2 and 10 in front of H2O i.e
2C4H10 + 13O2 → 8CO2 + 10H2O
Next divide through by 2,we have
C4H10 + 6.5O2 → 4CO2 + 5H2O
From the above illustration, we see that the coefficient of O2 is 6.5