Question

multiple - choice question
how does sulfur trioxide react in the atmosphere?
it reacts with nitrogen gas to form hydrogen sulfide
it reacts with ammonia to form sulfate salts
it reacts with water to form sulfuric acid
it reacts with oxygen to form sulfur dioxide
rewatch

Explanation:

Sulfur trioxide ($SO_3$) is an acidic oxide. In the atmosphere, it reacts with water vapor to form sulfuric acid ($H_2SO_4$), which is a key component of acid rain. The reaction is $SO_3 + H_2O
ightarrow H_2SO_4$. Other options are incorrect: it does not react with nitrogen gas to form hydrogen sulfide, reacts with ammonia to form ammonium sulfate (not sulfate salts generally as the primary atmospheric reaction), and does not react with oxygen to form sulfur dioxide (it is already a higher oxide of sulfur).

Answer:

it reacts with water to form sulfuric acid