Normally if is a conjuction, but is used as a noun in the expression ifs and buts, e.g. no ifs and buts.
A noun is used as the subject of the object of a sentence or phrase.
With is normally used as a preposition, denoting nearness (she is standing with John); association or connection (I work with my father); in the company of (I will come with Jane).With can also be...
Any time you refer to it as a thing - chocolate bar, chocolate chip cookie, hot chocolate, dark chocolate - all nouns.
One way that I can think of is in the example: "You have to wait in line for your turn."