Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Unit
Principles of Chemistry
991 practice questions
Topics covered
- States of Matter102 practice questions
- Elements, Compounds and Mixtures69 practice questions
- Atomic Structure108 practice questions
- The Periodic Table103 practice questions
- Chemical Formulae, Equations and Calculations Part 119 practice questions
- Chemical Formulae, Equations and Calculations Part 2144 practice questions
- Ionic Bonding143 practice questions
- Covalent Bonding68 practice questions
- Metallic Bonding19 practice questions
- Electrolysis198 practice questions
Practice questions
121–130 of 991
Question 121
2 marks · Hard
Answer and see the solution →Give one way in which the proportions of substances in a mixture are different from those in a compound. Use an example to support your answer.
Question 122
1 mark · Easy
Answer and see the solution →Name the separation technique used to obtain coloured components from an ink sample.
Question 123
3 marks · Easy
Answer and see the solution →A student has a mixture of iron filings and sulfur powder. They want to separate the two substances.
(a)[1 mark]State one physical property that can be used to separate iron filings from sulfur powder.
(b)[1 mark]Describe the separation technique they should use.
(c)[1 mark]Explain why this technique does not work for separating iron that has chemically reacted with sulfur.
Question 124
2 marks · Easy
Answer and see the solution →Explain why crystallisation is a good technique for separating sodium chloride from its aqueous solution.
Question 125
1 mark · Easy
Answer and see the solution →State the name of the technique used to separate an insoluble solid from a liquid.
Question 126
3 marks · Easy
Answer and see the solution →The diagram shows the apparatus used for simple distillation.
Apparatus for simple distillation (a)[1 mark]Name the liquid collected in the beaker.
(b)[1 mark]Give the name of the process shown.
(c)[1 mark]Explain why the salty water is heated in this process.
Question 127
2 marks · Easy
Answer and see the solution →A mixture of water and ethanol is heated. Water has a boiling point of 100°C and ethanol has a boiling point of 78°C. If the thermometer reads 78°C while distillate is being collected, which liquid is distilling over? Calculate how many degrees lower this temperature is than the boiling point of water.
Question 128
2 marks · Easy
Answer and see the solution →A sample of rock salt contains 16 g of sodium chloride mixed with 4 g of insoluble impurities. A student dissolves the sample in water, filters the solution, and then uses crystallisation to obtain sodium chloride crystals. What is the maximum mass of sodium chloride crystals the student can expect to obtain after crystallisation? Assume no losses occur during the process.
Question 129
3 marks · Easy
Answer and see the solution →A student carries out chromatography to separate the dyes in two different food colourings, X and Y. The chromatogram below shows the results. Each spot represents a dye.
Chromatogram showing dyes in colourings X and Y (solvent front at 10 cm, start line at 0 cm, each dye marked as a spot). (a)[1 mark]How many different dyes are present in colouring X?
(b)[1 mark]Which dye(s) are found in both X and Y?
(c)[1 mark]Suggest why one dye in X reached the top of the chromatogram while another travelled only a short distance.
Question 130
2 marks · Normal
Answer and see the solution →State one separation technique that could be used to obtain pure water from salty water, and one technique that could be used to obtain pure salt from salty water.