Question

When iron pyrite (FeS2) is heated in air, the process known as "roasting" forms sulfur dioxide and iron(III) oxide. When the equation for this process is completed and balanced, using the smallest whole number coefficients, what is the coefficient for "O2"?
___ FeS2 + ___ O2 → ___ SO2 + ___ Fe2O3

Answer 1

Answer:

The coefficient of O2 is 11

Explanation:

Step 1:

The equation for the reaction:

FeS2 + O2 → SO2 + Fe2O3

Step 2:

Balancing the equation. The equation can be balance as follow:

FeS2 + O2 → SO2 + Fe2O3

There are 2 atoms of Fe on the right side and 1 atom on the left. It can be balance by putting 2 in front of FeS2 as shown below:

2FeS2 + O2 → SO2 + Fe2O3

There are 4 atoms of S on the left side and 1 atom on the right side. It can be balance by putting 4 in front of SO2 as shown below:

2FeS2 + O2 → 4SO2 + Fe2O3

Now, there are a total of 11 atoms of O on the right side and 2 atoms on the left side. It can be balance by putting 11/2 in front of O2 as shown below:

2FeS2 + 11/2O2 → 4SO2 + Fe2O3

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

4FeS2 + 11O2 → 8SO2 + 2Fe2O3

Now the equation is balanced.

The coefficient of O2 is 11