Method of Separation
I have sand and iron.
Describe a method I could use to separate these substances.
Hand picking
Sieving
Magnet
A student says, “This object feels hard and keeps its shape.” What state of matter are they describing, and how do they know?
What is a solid? A solid keeps its shape and has a fixed volume.
A student is heating water using a hot plate and reaches out to touch the beaker with their bare hand. What is the risk, and what should they do instead?
What is a burn risk? They should use tongs, heatproof gloves, or allow the beaker to cool before touching it.
I am a mixture you might find at the beach. I contain tiny rock particles and salty water. What am I?
What is seawater with sand?
You have a mixture of iron filings and sand. Describe how you would separate the iron filings from the sand.
What is magnetic separation? Move a magnet over or through the mixture. The iron filings will be attracted to the magnet, leaving the sand behind.
You have a clear liquid in a beaker. Describe one physical property you could observe without changing what the substance is.
What is colour, smell, state, transparency, volume, or texture? Example: You could observe that it is colourless and transparent.
A student leaves their school bag in the walkway during a prac lesson. What is the risk, and how can it be reduced?
What is a trip hazard? Bags should be stored under benches or in the correct area away from walkways.
I can pick up iron filings without touching them, but I cannot pick up sand. What am I?
What is a magnet?
You have a mixture of salt and water. Describe how you would separate the salt from the water.
What is evaporation? Gently heat the salt water so the water evaporates, leaving the salt crystals behind.
A substance can dissolve in water. What property of matter is being described, and how could you test it?
What is solubility? Add the substance to water and stir to see whether it dissolves.
A student is pouring a liquid into a funnel but is not wearing safety glasses. What is the risk, and what should they do?
What is a splash risk? They should wear safety glasses to protect their eyes.
I let water pass through but trap sand. In the lab, I usually sit inside a funnel. What am I?
What is filter paper?
You have a mixture of gravel and sand. Describe how you would separate the gravel from the sand.
What is sieving? Pour the mixture through a sieve. The smaller sand particles pass through the holes, while the larger gravel pieces stay in the sieve.
A student has two unknown solids. One is attracted to a magnet and one is not. What property is being tested, and how would they test it safely?
What is magnetism? Move a magnet close to each solid and observe whether either solid is attracted to it.
A student smells an unknown chemical by putting their nose directly over the container. What is the risk, and what is the safer method?
What is inhaling harmful fumes? They should not directly smell chemicals. If instructed, they should waft the smell gently towards their nose.
I am a mixture of different coloured dyes. A scientist can separate my colours using paper and water. What method is being used?
What is chromatography?
You have a mixture of sand, salt and water. Describe the steps you would use to separate all three substances.
What are filtration and evaporation? First, filter the mixture so the sand stays in the filter paper and the salt water passes through. Then gently heat the salt water so the water evaporates, leaving the salt behind.
You have a mixture of sand, salt and iron filings. Explain how the properties of each material help you choose separation methods.
What are magnetism, solubility and particle size? Iron is magnetic, so use a magnet. Salt is soluble in water, so it dissolves. Sand is insoluble and can be removed by filtration. Salt can then be collected by evaporation.
During an evaporation experiment, a student heats salt water and then tries to move the hot evaporating dish across the bench while other students are nearby. Identify two risks and explain how to reduce them.
What are burn and spill risks? Use tongs or heatproof gloves, keep the area clear, move slowly, and allow equipment to cool before handling.
A student finds a mystery mixture with iron filings, sand, salt and small pebbles. Describe a sensible order of separation methods they could use.
What are magnetic separation, sieving, filtration and evaporation? Use a magnet to remove iron filings, sieve to remove pebbles, add water to dissolve salt, filter to remove sand, then evaporate the water to collect salt.