Why does heat speed up reactions?

Question

Why does heat speed up reactions?

In: 1

Answer 1

We express chemical reactions using stoichiometry; A + B -> C means 1 molecule of A reacts with 1 molecule of B to make 1 molecule of C.

But realistically, we don’t care about that 1 molecule of A/B/C, we care about huge numbers of molecules (Avogadro’s number, 6.022×10^22 molecules). In order for those vast numbers of reactions to happen, we need tons of A molecules hitting tons of B molecules all the time. Heat helps this because a substance at higher temperature mixes more easily and moves (internally) faster. That means more A’s bumping into B’s making more C’s.