I found these two sentences in "A Dictionary of Basic Japanese Grammar" under に(purpose):
学生が質問をしに来た。 A student came to ask questions.
そこへ何をしに行くんですか。For what are you going there?
When I look up し in the grammar dictionary its listed as "a conjunction to indicate 'and' in an emphatic way", which doesn't fit as far as I can tell. When I look し up in a regular dictionary all the words are nouns. What does it mean?