Equilibrium Explorer
Work an equilibrium problem one step at a time, with feedback at every step. Or explore freely: type any reaction and watch Q chase K.
Choose a problem
1 Write the K expression
Products on top, starting materials on the bottom, each raised to its coefficient. Pure solids and liquids are left out.
2 Which way does it go?
Put the starting amounts into the K expression to get Q, then compare Q with K.
3 Fill in the Change row
Let x be how far the reaction goes. Each species changes by its coefficient × x: minus if it is used up, plus if it forms.
4 Set up the equation
Equilibrium = Initial + Change. Put the equilibrium row into the K expression.
5 Solve for x
6 Equilibrium concentrations
Plug x back into the Equilibrium row.
1 Reaction
Use + between species and = or <=> for the arrow. Mark solids (s) and pure liquids (l); they stay out of K. Charges go at the end: H3O+, CH3COO-.
2 K and starting amounts
3 Disturb it
Change something after equilibrium is reached. Q is calculated right away and compared with K.
0.5 means the container is squeezed to half its volume, so every concentration doubles. 2 means it doubles in volume.
Only temperature changes K. Q stays the same at the instant K changes.