When will reactions proceed to completion?

Question

That's all my prelab asks. What does that mean and what is the answer? I put "When all of the reactants involved have fully reacted, leaving excess product behind."

Answer 1

Reactions will proceed to completion when there is something driving them to completion. For example:

1) There is a gas formed.

2) There is a precipitate formed.

3) There is a slightly ionized substance formed, like water.

All of these processes take product out of the reaction and so drive it to completion.