<Dl> <Dd> HOSO + O → HO + SO </Dd> </Dl> <Dd> HOSO + O → HO + SO </Dd> <P> In the presence of water, sulfur trioxide (SO) is converted rapidly to sulfuric acid: </P> <Dl> <Dd> SO (g) + H O (l) → H SO (aq) </Dd> </Dl>

When was the last time there was acid rain