Workshop 7 - Separating MIxtures
After completing the experiment, in your group write up your own version of the experiment use the experimental design headings:
Title, Aim, Hypothesis, Materials, Methods, Results, Discussion Questions, Conclusion
Practical: Separating Mixtures
TITLE: How doe we separate the individual components of mixtures?
AIM: To use the technique of filtering to separate sand salt and water from a mixture.
MATERIALS: Needs to be done in groups of 2-3 people.
- Eye protection
- 8 grams of Sand
- 2 grams of Salt
- 50mls of water
- Beaker (250 cm3)
- Stirring rod
- Filter funnel
- Filter paper
- Conical flask to pour beaker contents into.
- Mix of 8 grams of sand and 2 grams of sodium chloride (salt) in a dish, using scales. Remember to press tare before you begin to add the sand, then again when you add the salt.
- Pour the sand-salt mixture into the beaker so that it just covers the base
- Add about 50 mls of water, or add water until the beaker is about one-fifth full.
- Stir the mixture gently for a few minutes.
- Pour the water, sand and salt mixture through the filter paper.
- Record what is left behind on the filter paper.
- Record what is left in the filter paper.
- What is left in the conical flask?
- Why can sand and salt be separated using this experiment?
- Why is the salt, sand and water mixture stirred in step 4?
- If the filter paper separates the sand out, how can we separate the salt from the remaining water? What equipment would you need.
- How might the final traces of water be removed from your samples to ensure that they’re totally separated?
- Give two reasons why the sand you have obtained might still be contaminated with salt.
- How could you adapt your experiment to obtain a purer sample of sand?
- Give two reasons why the salt you have obtained might still be contaminated with sand.