Question

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

Answer 1

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.