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.

option A.