Question

balance the following reaction. what is the stoichiometric coefficient for fes₂?
fes₂ + o₂ → fe₂o₃ + so₂

Explanation:

Step1: Balance Fe atoms

Let the coefficient of \(FeS_2\) be \(x\) and of \(Fe_2O_3\) be \(y\). For Fe atoms: \(x = 2y\). Let \(y = 1\), then \(x = 2\).

Step2: Balance S atoms

If \(FeS_2\) coefficient is \(2\), then for S atoms (since each \(FeS_2\) has \(2\) S atoms), the coefficient of \(SO_2\) is \(4\) (because \(2\times2=4\)).

Step3: Balance O atoms

The right - hand side has \(3\) (from \(Fe_2O_3\)) \(+ 4\times2\) (from \(SO_2\)) \(=3 + 8=11\) O atoms. The left - hand side has \(O_2\). Let the coefficient of \(O_2\) be \(z\). Then \(2z=11\), \(z=\frac{11}{2}\). Multiply all coefficients by \(2\) to get rid of the fraction. The balanced equation is \(4FeS_2+11O_2
ightarrow2Fe_2O_3 + 8SO_2\).

Answer:

\(4\)