Video Transcript
Give a balanced equation for the reaction
used to convert elemental sulphur S₈ to a sulphur-containing gas for use as a reactant in
the contact process.
The contact process is a way of making
sulfuric acid. What we need to do is find a step of the
contact process that involves sulphur that generates a sulfur-containing gas. The only step of the contact process that
involves elemental sulphur is the first one, where sulphur can be converted into sulphur
dioxide. This is done by burning sulphur using
oxygen from the air.
So, we know our reactants are sulphur and
oxygen, and that our product is sulphur dioxide. We know this is the right answer because
sulphur dioxide is used as a reactant in the second step of the contact process. So, our answer starts off with S₈. We react it with oxygen. And we produce sulphur dioxide.
The next step is to check that this
equation is balanced. As you can see, we have enough oxygen on
both sides, but we’re lacking sulphur in the products. If we increase the number of sulphur
dioxide molecules to eight, we get eight sulphur atoms on both sides. However, it means that we bring the
oxygens out of balance. So, to finish off, we just need to add
seven more oxygen molecules to the reactants, bringing the number of oxygen atoms to 16 on
both sides.
So, the balanced equation for the
reaction that’s used to convert elemental sulphur to a sulphur-containing gas for use as a
reactant in the contact process is S₈ plus 8O₂ react to form 8SO₂.
