Which of the following combustion reactions is balanced correctly? A. C4H6 + 5.5O2 4CO2 + 3H2O B. C4H6 + 4O2 4CO2 + 3H2O C. C4H6 + 11O2 4CO2 + 3H2O D. C4H6 + 1.5O2 4CO2 + 3H2O

You must verify that the number of atoms of each type is equal on both sides of the chemical equation: same number of C, same number of H and same number of O on both sides.

A. C4H6 + 5.5O2 - - - > 4CO2 + 3H2O

element reactant side product side

C 4 4

H 6 3*2 = 6

O 5.5 * 2 = 11 4*2 + 3 = 11

Then, this equation is balanced.

Do the same with the other equations if you want to verify that they are not balanced.

Answer: option A.