Making a Precipitate

Two clear solutions are poured together. Each is made of ions drifting freely. When they meet, the ions trade partners — and if one of the new pairs will not dissolve, it clumps together and sinks as a solid you can see. That solid is the precipitate.

Pick two solutions, then press Mix Watch which ions pair up and sink The other pair stays dissolved and invisible

Choose two solutions and press Mix.

The two solutions

Solution A

Solution B

Every solution here is colourless and clear to start with. The ions are already there — you just cannot see them until a reaction makes a solid.

What forms

Press Mix to pour them together.

Ions in the mix

A precipitate forms only when one of the new pairings is insoluble. If both new pairs dissolve, nothing visible happens.