Question

Explain how sulfur dioxide, as emitted by some power plants, ends up as sulfuric acid (H2SO4), and sulfate ion (SO42-) in rivers and lakes.
Be brief, 2-4 sentences should be enough.

Answer 1

Explanation:

Sulphur dioxide is oxidised by the oxygen in the atmosphere to form sulphur trioxide, the major component in acid rain.

2SO2 + O2 - - > 2SO3

The subsequent Sulphur trioxide reacts with water in the rain/lake/river to form sulphuric acid.

SO3 + H20 - - > H2SO4

The sulphuric acid undergoes ionisation to form:

In major quantities ;

H2SO4 <----> H+ + HSO4-

And

In smaller quantities to form sulphate ion;

H2SO4 <---> 2H+ + SO4^-2