1. Balance the following equations:

a. -

C8H18 (1) + ___02 (g) +

CO2 (g) +

H2O (1)

1. 2C8H18 + 25O2 - > 16CO2 + 18H2O

2. The coefficient of O2 is 25

Explanation:

C8H18 + O2 - > CO2 + H2O

The above equation can be balance as follow:

There are 8 atoms of C on the left side and 1 atom on the right side. It can be balance by putting 8 in front of CO2 as shown below:

C8H18 + O2 - > 8CO2 + H2O

There are 18 atoms of H on the left side and 2 atoms on the right. It can be balance by putting 9 in front of H2O as shown below:

C8H18 + O2 - > 8CO2 + 9H2O

Now, there are a total of of 25 atoms of O on the right side and 2 atoms on the left side. It can be balance by putting 25/2 in front of O2 as shown below:

C8H18 + 25/2O2 - > 8CO2 + 9H2O

Multiply through by 2 to clear the fraction as shown below:

2C8H18 + 25O2 - > 16CO2 + 18H2O

Now the equation is balanced.

2. 2C8H18 + 25O2 - > 16CO2 + 18H2O

From the balanced equation above, the coefficient of O2 is 25