Science Common Sense

1769 - What is the definition and calculation of equilibrium constant.

Imagine you have a see-saw with kids on both sides. When both sides are balanced, the see-saw doesn't move. That's similar to what happens in chemistry, when a reaction reaches a balance between the reactants and products.

The equilibrium constant (K) is a number that shows how much of the reactants and products are present when the reaction reaches balance.

Here's the formula: K = [Products] / [Reactants]

For example, if we have a simple reaction: A + B → C + D

The equilibrium constant (K) calculation would be: K = [C] [D] / [A] [B]

• [A], [B], [C], and [D] are the concentrations of each substance, which is the amount of that substance per unit volume.

A high K value means the reaction favors the products (more C and D), while a low K value means it favors the reactants (more A and B).

Think of the equilibrium constant like a report card for the reaction. It tells you how well the reaction is doing at reaching a balance between the reactants and products.