Edexcel GCSE Combined Science Chemistry, Foundation tier sample questions and answers (1SC0)
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35 sample questions and answers
Taken from every topic of Edexcel GCSE Combined Science Chemistry, Foundation tier, specification 1SC0. The full guide has 1,206.
Paper 3, Paper 4
Key Concepts in Chemistry
359 questions in the guide, across 27 subtopics. More from this topic
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Formulae, word equations and balanced equations
Give the formulae of calcium carbonate and sodium hydroxide.
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They are CaCO₃ and NaOH. -
Protons, neutrons and electrons
Which subatomic particle has a mass so small it is treated as negligible?
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The electron has a negligible mass compared with a proton or a neutron. -
Calculating particle numbers and relative atomic mass
An atom of fluorine has atomic number 9 and mass number 19. How many neutrons does it have, and how is this worked out?
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It has 10 neutrons, found by subtracting the atomic number from the mass number: 19 − 9 = 10. -
Electronic configuration and the periodic table
Write the electronic configuration of a calcium atom.
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Calcium is 2.8.8.2. -
Formulae of ionic compounds
Deduce the formula of aluminium oxide from the ions Al³⁺ and O²⁻.
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The formula is Al₂O₃.
Paper 3
States of Matter and Mixtures
118 questions in the guide, across 8 subtopics. More from this topic
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The three states of matter and changes of state
Put the three states of matter in order of increasing energy of their particles.
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Solid particles have the least energy, liquid particles have more, and gas particles have the most. -
Energy changes during changes of state, and predicting state
Why does the temperature stay constant while a pure solid is melting?
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The energy supplied is used to overcome the forces between the particles rather than to make them move faster. -
Pure substances and melting point data
State one way in which the properties of a mixture differ from those of a pure substance.
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Each substance in a mixture keeps its own properties, while a pure substance has one fixed set of properties. -
Choosing a separation technique
Why would crystallisation be chosen instead of distillation to obtain salt from salt solution?
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Crystallisation is used when only the dissolved solid is wanted and the solvent does not need to be kept. -
Separating a mixture in practice
A mixture contains sand and salt. Describe how to obtain dry salt from it.
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Add water and stir to dissolve the salt, filter off the sand, then crystallise the salt from the filtrate.
Paper 3
Chemical Changes
222 questions in the guide, across 16 subtopics. More from this topic
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Acids, alkalis and the pH scale
Explain why hydrogen chloride only behaves as an acid once it has dissolved in water.
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Only in solution does it release hydrogen ions, and these ions are what make a solution acidic. -
Investigating pH change when neutralising an acid
Explain why the pH stops rising once excess calcium hydroxide has been added to dilute hydrochloric acid.
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Calcium hydroxide is only slightly soluble, so once the acid is neutralised the solution soon becomes saturated and no more hydroxide ions can dissolve. -
Reactions of acids, and testing for hydrogen and carbon dioxide
Name the salt formed when zinc oxide reacts with dilute sulfuric acid.
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Zinc sulfate is formed. -
Preparing soluble salts from insoluble and soluble reactants
Explain why leaving unreacted acid in the mixture would spoil a salt prepared this way.
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The acid would stay in the solution and contaminate the crystals when the water is evaporated. -
Carrying out an acid-alkali titration
Describe how a pure, dry salt is made once the volume of acid needed to neutralise the alkali is known.
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The same volumes are mixed again with no indicator, and the solution is then evaporated and crystallised.
Paper 3
Extracting Metals and Equilibria
99 questions in the guide, across 8 subtopics. More from this topic
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Investigating the reactivity of metals
What is seen when magnesium is added to cold water, and what does this show about its reactivity?
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Only a few bubbles appear very slowly, showing magnesium is less reactive than sodium or calcium. -
The reactivity series
Which metals of the reactivity series react with dilute acids but show almost no reaction with cold water?
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Magnesium, aluminium, zinc and iron react with dilute acids but barely react with cold water. -
Ores, oxidation and reduction
Why is aluminium never found in the Earth’s crust as the uncombined element?
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Aluminium is reactive, so it is always found joined to other elements in compounds. -
Choosing a method to extract a metal
Why can aluminium not be extracted by heating its oxide with carbon?
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Aluminium is more reactive than carbon, so carbon cannot take the oxygen away from aluminium oxide. -
Corrosion resistance and recycling metals
Why does aluminium resist corrosion even though it is high in the reactivity series?
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The oxide layer that forms on aluminium clings firmly to the surface and stops oxygen reaching the metal underneath.
Paper 4
Groups in the Periodic Table
99 questions in the guide, across 8 subtopics. More from this topic
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The groups of the periodic table, and the alkali metals
Why do elements in the same group of the periodic table have similar chemical properties?
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They have the same number of electrons in the outer shell, and the outer electrons decide how an element reacts. -
Reactions of the alkali metals with water
Name the two products formed when an alkali metal reacts with water.
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A metal hydroxide, which dissolves to give an alkaline solution, and hydrogen gas. -
The pattern in alkali metal reactivity and why it happens
Rubidium lies below potassium in group 1. Predict how it behaves when dropped into water.
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Rubidium reacts even more violently than potassium, because reactivity increases further down the group. -
Physical properties of the halogens
What colour is the vapour seen above iodine when it is gently warmed?
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The vapour is purple. -
The test for chlorine, and halogens reacting with metals
Why is blue litmus paper turning red not enough on its own to identify chlorine?
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Any acidic gas turns damp blue litmus red, so only the bleaching to white confirms chlorine.
Paper 4
Rates of Reaction and Energy Changes
119 questions in the guide, across 7 subtopics. More from this topic
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Investigating the rate of a reaction
Why is following loss of mass unsuitable when the gas produced is hydrogen?
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Hydrogen has such a low mass that the balance shows almost no change. -
Investigating the rate of a reaction
Why must the same flask and the same total volume of liquid be used for every run of the sodium thiosulfate experiment?
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The amount of sulfur needed to hide the cross depends on the depth of liquid, so it must be kept constant for a fair comparison. -
Measuring rate and interpreting rate graphs
Suggest why a datalogger connected to a balance gives better results than reading the balance by eye.
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A datalogger records readings at exactly equal intervals and does not miss a reading, so the data are more reliable. -
Measuring rate and interpreting rate graphs
A flask loses 2.4 g of mass in 120 s. Calculate the mean rate of the reaction in g s⁻¹.
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2.4 ÷ 120 = 0.02 g s⁻¹. -
Collision theory and factors affecting rate
Explain why a reaction between two solids is usually extremely slow.
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Only the particles at the touching surfaces can collide, so collisions are very infrequent.
Paper 4
Fuels and Earth Science
190 questions in the guide, across 12 subtopics. More from this topic
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Hydrocarbons and crude oil
A compound has the formula C₃H₇Cl. State whether it is a hydrocarbon and explain your answer.
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It is not a hydrocarbon because it contains chlorine in addition to carbon and hydrogen. -
Fractional distillation and the fractions
Name the crude oil fraction used to surface roads and roofs.
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Bitumen is used to surface roads and to cover roofs. -
Complete and incomplete combustion
Write the balanced equation for the complete combustion of methane.
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CH₄ + 2O₂ → CO₂ + 2H₂O. -
Carbon monoxide and soot
Describe one visible sign that a gas appliance is burning its fuel incompletely.
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The flame burns yellow or orange instead of blue, and black sooty marks appear around the appliance. -
Hydrogen and fossil fuels compared
Explain why hydrogen is considered hazardous as a car fuel.
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It is extremely flammable and forms explosive mixtures with air if it leaks.
Edexcel GCSE Combined Science Chemistry, Foundation tier Active Recall Guide
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