Ace the ACS Organic Chemistry Challenge 2026 – Unleash Your Inner Scientist!

Increasing surface area exposes more reactive sites, so more collisions can occur per unit time. When a solid reacts with a gas or liquid, breaking it into smaller pieces or grinding it into powder raises the area in contact with the other reactant. That larger contact area means more opportunities for collisions, which raises the collision frequency and typically speeds up the reaction (assuming there’s enough energy in those collisions for reaction to proceed). Temperature still affects whether those collisions lead to products, but surface area directly increases how often collisions happen.