The correct matching is the following:
1. Impervious. The prefix im- means not or without.
2. Inviolate. The prefix in- has the meaning of not or without.
3. Converge. The prefix con- means together or with.
4. Irrational. The prefix ir- means opposite of or not.
Prefixes are letters that are added before the stem or root to change its meaning. In this case, the prefixes are from neo-classical origin, meaning that they come from Greek and Latin instead of having an English basis.