How to Calculate Equilibrium Pressures

By Robert Schrader
Smoke image by peter Hires Images from

As you read your chemistry textbook, you may notice that some reactions are written with arrows that point in both directions. This signifies that a reaction is reversible--that the reaction's products can re-react with one another and re-form the reactants. The point at which a reaction occurs at the same rate in both directions is known as equilibrium. When gases react at equilibrium, it's possible to calculate their pressures using a number known as the equilibrium constant, which is different for each reaction.

About the Author

Robert Schrader is a writer, photographer, world traveler and creator of the award-winning blog Leave Your Daily Hell. When he's not out globetrotting, you can find him in beautiful Austin, TX, where he lives with his partner.