Which of these images shows a pure compound?
Which is the correct description of these particles?
A mixture of compounds
A mixture of elements and compounds
A mixture of elements
How does filtration work?
The solid particles are too large to pass through the filter
The solvent has a very high boiling point
The solid is very soluble in the solvent
Which is the best way to obtain a sample of salt from a salt solution?
Filtration
Crystallisation
Fractional distillation
Which is the correct order for obtaining salt from a mixture of sand and salt?
Dissolving in water - filtration - crystallisation
Crystallisation - filtration - dissolving in water
Filtration - dissolving in water - crystallisation
What property difference allows mixtures of liquids to be separated by fractional distillation?
Density
Boiling point
Solubility
Which method is usually used to separate and identify coloured dyes from each other?
Chromatography
Simple distillation
Crude oil can be separated into several liquids that have different boiling points. What is the name of this process?
What is chlorine used for in water treatment?
To remove soluble substances
To kill harmful microorganisms
To clump smaller insoluble particles together
Where are the spots of the samples placed in chromatography?
Randomly on the piece of paper
In a vertical line on the paper
In a horizontal line on the paper