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Separating mixtures
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Experiment Worksheet, Page 3
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Below shows an example Experiment Worksheet for separation of water from a salt (Time: about 1 hour).
1. Question (initial assessment prior to experiment)
Does salt dissolve in water? (YES)
What is the boiling point of water (100°C)
Which separation technique is suitable to separate salt and water ? (Distillation)
Draw a labelled diagram for the experiment.
2. Set up the experiment, as shown in the diagram drawn.
- Make sure that the water going into the condenser is from the lower inlet.
- The condenser should be supported by a clamp and stand.
- Stop the experiment once you collect a reasonable amount of liquid in the beaker.
Observe the progress of the experiment and write down the observation.
(a) What do you observe inside the flask at 100°C?
(b) What do you observe in the condenser at 100°C?
(c) What do you collect in the beaker?
(d) What is remained in the flask?
3. Questions and further discussions.
These questions can be tricky. They stimulate pupils' interest and give further understanding about the subject.
1. What separation technique do we use if we are to separate water from a solution of an insoluble solid? Can you name one insoluble solid in water?
2. Can we use Evaporation to separate water from the salt solution for this experiment? Why?
3. If the salt solution contains another soluble solid (say sugar), do you think the experiment would be carried out differently in order to get the same result?
4. How do you know that the liquid collected in the beaker is water?
5. What are the common names for the three states of water?
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