crystallisation (deck 6)

What is the purpose of the evaporation dish experiment?

To separate a dissolved solid from a solution by evaporating the liquid.

What do you pour into the evaporating dish?

A solution like saltwater.

Where do you place the evaporating dish?

On a tripod and gauze above a Bunsen burner.

What do you do with the Bunsen burner?

Gently heat the solution to evaporate the water.

What is left behind after evaporation?

The solid that was dissolved in the solution (e.g. salt).

Why do you use gentle heating?

To avoid splashing and damaging the solid.

What safety precautions should you take?

Wear goggles, use a heatproof mat, and handle hot equipment carefully.

Why do we gently heat the solution?

To partially evaporate the water making the solution more concentrated so that crystals can form when it cools

Gently heating avoids decomposing the solute or forming impure solids