Question

What is the chemical formula of sulphur trioxide?

Answer 1

Sulfur trioxide - `SO_"3"`.

Explanation:

Sulfur trioxide: `SO_"3"`.

How I came to this conclusion:

I noticed that the compound consists of non-metals, therefore it must be a covalent compound - meaning I use prefixes for compounds.

Sulfur is `S`. Simple enough. Trioxide has the prefix of tri, meaning "3". Therefore there is 3 atoms of oxygen. Combine them and I get `SO_"3"`.

Don't be confused with sulfite: `(SO_"3")^(2-)` and sulfate: `(SO_"4")^(2-)`

Hope this helps :)