Students make sugar solutions of different concentrations and colour them using food colouring. They then use them to make a density column in a test tube, with a challenge to see how many different layers they can create.
- miscibility of liquids (whether they mix or form layers)
- states of matter – liquids (addressing the common misconception that all liquids are water-based)
- properties of materials – miscibility is an extension on the concept of solubility
- careful handling of chemicals
- planning scientific enquiries to answer questions
- recording data
- using test results to make predictions
Prior learning required
Students may have some experience of recording data in a table of results.
Further study ideas
- Application: Can you make layers using liquids found in the kitchen (golden syrup, milk, water, vegetable oil).
- Application: Make lava lamps using vegetable oil, water and food colouring.
- Mystery: Egg which floats in salt water but sinks in pure water – can students work out what the trick is?
- Mystery: Raisins in lemonade – why do they float and then sink again?
- Investigation: how much washing up liquid is needed to make oil and water mix?
- Investigation: How do solids float differently in different liquids? Does shape matter?