Does transforming a CFG to Chomsky normal form make it unambiguous?
There are inherently ambiguous context-free languages, and like all context-free languages they have grammars in Chomsky normal form, so transforming a CFG to Chomsky normal form doesn't necessarily make it unambiguous. For the same reason there is no technique to convert an arbitrary context-free grammar to one which in unambiguous.

Deciding whether a given context-free grammar is ambiguous, or whether a given context-free grammar generates an inherently ambiguous language, is undecidable. This doesn't necessarily mean that there is no procedure that converts any context-free grammar into an unambiguous one given that the language isn't inherently unambiguous, but it does make the existence of such an algorithm somewhat doubtful.