GCSE Chemistry – States of Matter and Mixtures – 3 -Exam Style Questions with Answers

Substances can be pure or they can be mixtures.
Which of these is a mixture?

Filtration is a method used to separate insoluble solids from liquids.
Figure 9 shows the apparatus used for filtration.
Which letter shows the filtrate? 

P, Q,R and S are mixtures of food colourings.
They are investigated using paper chromatography.
Figure 13 shows the chromatogram at the end of the experiment
Which mixture contains an insoluble food colouring?

An ink is a mixture of coloured substances dissolved in water.
Which method is used to separate the coloured substances in the ink? 

Some food colourings are a mixture of soluble, coloured substances. Mixtures of soluble substances can be separated by paper chromatography.
Paper chromatography was used to try to separate the coloured substances in five food colourings, V, W, X, Y and Z.
Figure 10 shows the spots for the five food colourings on the chromatography paper at the start of the experiment.
The paper was placed in a beaker with the bottom of the paper in the solvent.

Which of the following is not a pure substance?

Potable water is water that is suitable for drinking.
River water can be treated to make it potable. Chlorination, filtration and sedimentation are three of the processes involved in making the river water potable.
Which row of the table shows these three processes in the order in which they are carried out?

Inks contain coloured dyes. Samples of four inks, W, X, Y and Z, were separated using paper chromatography.
Figure 5 shows the chromatogram obtained

Titanium is extracted from its ore in several stages. In the first stage, titanium chloride is formed as a gas.
The gas is cooled to form liquid titanium chloride containing dissolved impurities.
Suggest how pure titanium chloride could be separated from the impurities.

Mixtures of substances can be separated using different techniques.

Which of the following is a mixture of substances?

Waste water can be used to produce drinking water.
The processes used include sedimentation, filtration and chlorination.
What is sedimentation?