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
101–110 of 991
Question 101
6 marks · Normal
Answer and see the solution →A teacher asks the class to consider a scenario: 'Chlorine gas and a solid sugar cube are each placed in the opposite ends of two sealed glass tubes filled with air. Both tubes are left for several hours at room temperature.'
(a)[2 marks]Explain what happens to the chlorine gas in terms of diffusion.
(b)[2 marks]Describe what would happen to the sugar cube over time and give a reason using particle ideas.
(c)[2 marks]State what is meant by a solution, referring to both the sugar experiment and the key terms 'solute' and 'solvent.'
Question 102
8 marks · Hard
Answer and see the solution →A student is investigating the solubility of a salt, ammonium nitrate (NH₄NO₃), in water. They perform an experiment and obtain the following results:
(a)Experimental masses Item Mass / g Empty evaporating basin 26.47 Evaporating basin + solution 62.12 Evaporating basin + dry crystals 40.11 Using the results above, calculate the solubility of ammonium nitrate at 35°C in g per 100g of water.
(i)[1 mark]Calculate the mass of crystals and mass of water used.
(ii)[2 marks]Calculate the solubility (g per 100g of water).
(b)The student repeats this experiment at different temperatures and obtains the following solubility data:
Temperature/°C Solubility / g per 100g water 10 65 20 77 35 98 55 138 Explain, using your result from part (a), how the student could check that their measurement at 35°C fits the trend shown by the other data points. What pattern would you expect to see on a solubility curve for this salt?
(i)[1 mark]What does the solubility curve show about the relationship between temperature and solubility for ammonium nitrate?
(ii)[1 mark]State how a result that does NOT fit the trend would appear on a solubility curve.
(c)[1 mark]Give the correct term for a solution in which no more solute can dissolve at a particular temperature, and undissolved solid is present.
(d)[1 mark]State the equation used to calculate solubility in g per 100g of water from experimental mass data.
(e)[1 mark]Explain briefly why it is important to pour off only the solution and not any undissolved solid during the experiment.
Question 103
1 mark · Easy
Answer and see the solution →State whether sodium chloride (table salt) is an element, a compound, or a mixture.
Question 104
3 marks · Easy
Answer and see the solution →The table below shows the melting points of three samples. Use the data to answer the questions.
Melting points of three substances Sample Melting point (°C) A 801 B 112–130 C 0 (a)[1 mark]Which sample is a pure substance? Explain your answer.
(b)[1 mark]State what the melting range in sample B tells you about its purity.
(c)[1 mark]The boiling point of sample C is 100°C. Is C most likely a pure substance or a mixture? Give a reason.
Question 105
2 marks · Easy
Answer and see the solution →Explain why a mixture of ethanol and water does not have a sharp boiling point.
Question 106
3 marks · Easy
Answer and see the solution →Classify each substance in the table as an element, a compound, or a mixture.
Classification of substances Substance Classification Argon Sea water Ammonia (NH₃) Question 107
1 mark · Easy
Answer and see the solution →State what you would observe about the melting behaviour of a pure substance.
Question 108
3 marks · Easy
Answer and see the solution →A student has the following substances:
Substance Description Hydrogen Colourless gas, only one kind of atom Calcium oxide Solid, contains calcium and oxygen chemically combined Air Mixture of different gases (a)[1 mark]Which substance is an element? Explain your answer.
(b)[1 mark]Which substance is a compound? State its chemical formula.
(c)[1 mark]Why is air described as a mixture?
Question 109
2 marks · Easy
Answer and see the solution →A liquid mixture has a boiling range from 83°C to 97°C. Calculate the difference in temperature across its boiling range.
Question 110
2 marks · Easy
Answer and see the solution →A sealed container holds 36 g of water and 12 g of oxygen gas. Calculate the total mass of compound present and the total mass of element present in the container. Identify which substance is a compound and which is an element.