What is the third step in making crystals?

• A. Filter, dry and collect the crystals.
• B. Leave to cool gradually.
• C. Heat to crystallisation.
• D. Stir the solution.

Answer: (A)

When crystals are being formed from a solution, the next important step after crystals have appeared is to separate them from the remaining liquid and remove any water. Filtering the mixture pours off the liquid while keeping the solid crystals behind, and drying them removes the water to leave dry crystals ready to weigh or observe. This step comes after you have prepared a saturated hot solution and allowed it to cool so crystals can form, so the sequence is to dissolve by heating, then let it cool to crystallize, and finally filter, dry and collect the crystals. The other actions fit earlier stages or are part of forming the crystals, not the final collection step.