A pure sample of the insoluble salt barium carbonate can be prepared by using the method below. step 1 Dissolve barium chloride in water. step 2 Separately dissolve sodium carbonate in water. step 3 Combine the two solutions. step 4 Filter the mixture. step 5 step 6 Dry the residue between two sheets of filter paper. What instruction should be inserted for step 5?
- AHeat the residue to dryness.
- BHeat the residue to the point of crystallisation.
- CPlace the filtrate in an evaporating basin.
- DWash the residue with water.