Arnold K H Tan's answer to Merlion's Secondary 1 Science Singapore question.
Can you explain 6 a again?
You have to plan out the separation of X, Y and Z, based on differences in property.
1. It is easiest to separate X, a magnetic material, from Y and Z by using a magnet.
2. For Y and Z, only one is soluble in water, so these can be separated by using water as a solvent, followed by filtration through filter paper.
It is necessary to wash the residue using distilled water, because after filtration, the wet residue still contains some of the filtrate solution. Analogy: if you collect sand from the sea floor, the wet sand is still contaminated with salty sea water.
As the question required a dry sample, you will need to carry out crystallisation of the filtrate. You cannot heat until dry, because the boiling points are low and very close to water, so the salt will just boil away with the water.
1. It is easiest to separate X, a magnetic material, from Y and Z by using a magnet.
2. For Y and Z, only one is soluble in water, so these can be separated by using water as a solvent, followed by filtration through filter paper.
It is necessary to wash the residue using distilled water, because after filtration, the wet residue still contains some of the filtrate solution. Analogy: if you collect sand from the sea floor, the wet sand is still contaminated with salty sea water.
As the question required a dry sample, you will need to carry out crystallisation of the filtrate. You cannot heat until dry, because the boiling points are low and very close to water, so the salt will just boil away with the water.
How about Y?
Y can separated by evaporation?
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