What is the object of preposition in sentence Where are we going for lunch?

The object of the preposition "for" in the sentence "Where are we going for lunch?" is lunch.

Here's why:

* Prepositional Phrase: "for lunch" is a prepositional phrase, consisting of a preposition ("for") and its object.

* Object of Preposition: The object of the preposition is the noun or pronoun that follows the preposition. In this case, it's "lunch."

The prepositional phrase "for lunch" tells us the purpose of our going.