Edexcel GCSE Chemistry, Foundation tier sample questions and answers (1CH0)

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45 sample questions and answers

Taken from every topic of Edexcel GCSE Chemistry, Foundation tier, specification 1CH0. The full guide has 1,651.

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Paper 1, Paper 2

Key Concepts in Chemistry

359 questions in the guide, across 27 subtopics. More from this topic

  1. Formulae, word equations and balanced equations

    Give the formulae of calcium carbonate and sodium hydroxide.

    Show the answer
    They are CaCO₃ and NaOH.
  2. Protons, neutrons and electrons

    Which subatomic particle has a mass so small it is treated as negligible?

    Show the answer
    The electron has a negligible mass compared with a proton or a neutron.
  3. 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?

    Show the answer
    It has 10 neutrons, found by subtracting the atomic number from the mass number: 19 − 9 = 10.
  4. Electronic configuration and the periodic table

    Write the electronic configuration of a calcium atom.

    Show the answer
    Calcium is 2.8.8.2.
  5. Formulae of ionic compounds

    Deduce the formula of aluminium oxide from the ions Al³⁺ and O²⁻.

    Show the answer
    The formula is Al₂O₃.

Paper 1

States of Matter and Mixtures

118 questions in the guide, across 8 subtopics. More from this topic

  1. 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.
  2. Energy changes during changes of state, and predicting state

    Why does the temperature stay constant while a pure solid is melting?

    Show the answer
    The energy supplied is used to overcome the forces between the particles rather than to make them move faster.
  3. Pure substances and melting point data

    State one way in which the properties of a mixture differ from those of a pure substance.

    Show the answer
    Each substance in a mixture keeps its own properties, while a pure substance has one fixed set of properties.
  4. Choosing a separation technique

    Why would crystallisation be chosen instead of distillation to obtain salt from salt solution?

    Show the answer
    Crystallisation is used when only the dissolved solid is wanted and the solvent does not need to be kept.
  5. Separating a mixture in practice

    A mixture contains sand and salt. Describe how to obtain dry salt from it.

    Show the answer
    Add water and stir to dissolve the salt, filter off the sand, then crystallise the salt from the filtrate.

Paper 1

Chemical Changes

222 questions in the guide, across 16 subtopics. More from this topic

  1. 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.
  2. Investigating pH change when neutralising an acid

    Explain why the pH stops rising once excess calcium hydroxide has been added to dilute hydrochloric acid.

    Show the answer
    Calcium hydroxide is only slightly soluble, so once the acid is neutralised the solution soon becomes saturated and no more hydroxide ions can dissolve.
  3. Reactions of acids, and testing for hydrogen and carbon dioxide

    Name the salt formed when zinc oxide reacts with dilute sulfuric acid.

    Show the answer
    Zinc sulfate is formed.
  4. Preparing soluble salts from insoluble and soluble reactants

    Explain why leaving unreacted acid in the mixture would spoil a salt prepared this way.

    Show the answer
    The acid would stay in the solution and contaminate the crystals when the water is evaporated.
  5. 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.

    Show the answer
    The same volumes are mixed again with no indicator, and the solution is then evaporated and crystallised.

Paper 1

Extracting Metals and Equilibria

99 questions in the guide, across 8 subtopics. More from this topic

  1. Investigating the reactivity of metals

    What is seen when magnesium is added to cold water, and what does this show about its reactivity?

    Show the answer
    Only a few bubbles appear very slowly, showing magnesium is less reactive than sodium or calcium.
  2. The reactivity series

    Which metals of the reactivity series react with dilute acids but show almost no reaction with cold water?

    Show the answer
    Magnesium, aluminium, zinc and iron react with dilute acids but barely react with cold water.
  3. Ores, oxidation and reduction

    Why is aluminium never found in the Earth’s crust as the uncombined element?

    Show the answer
    Aluminium is reactive, so it is always found joined to other elements in compounds.
  4. Choosing a method to extract a metal

    Why can aluminium not be extracted by heating its oxide with carbon?

    Show the answer
    Aluminium is more reactive than carbon, so carbon cannot take the oxygen away from aluminium oxide.
  5. Corrosion resistance and recycling metals

    Why does aluminium resist corrosion even though it is high in the reactivity series?

    Show the answer
    The oxide layer that forms on aluminium clings firmly to the surface and stops oxygen reaching the metal underneath.

Paper 1

Transition Metals, Quantitative Chemistry and Industrial Processes

149 questions in the guide, across 13 subtopics. More from this topic

  1. Transition metals and their properties

    State two typical physical properties of a transition metal.

    Show the answer
    Transition metals have high melting points and high densities.
  2. Corrosion and electroplating

    What must the electrolyte contain when an object is copper plated?

    Show the answer
    It must contain copper ions in solution, such as copper(II) sulfate solution.
  3. Alloys and alloy steels

    Suggest why adding a small amount of carbon to iron makes the metal much harder.

    Show the answer
    Carbon atoms are a different size from iron atoms, so they disrupt the layers and stop them sliding.
  4. How the uses of metals relate to their properties

    Which two metals are alloyed to make magnalium, and why is the alloy useful in aircraft parts?

    Show the answer
    Magnalium is an alloy of aluminium and magnesium that is stronger than aluminium while keeping a low density.
  5. Percentage yield

    A process has a theoretical yield of 20.0 g and a percentage yield of 45%. Calculate the actual yield.

    Show the answer
    0.45 × 20.0 = 9.0 g.

Paper 2

Groups in the Periodic Table

99 questions in the guide, across 8 subtopics. More from this topic

  1. 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.
  2. Reactions of the alkali metals with water

    Name the two products formed when an alkali metal reacts with water.

    Show the answer
    A metal hydroxide, which dissolves to give an alkaline solution, and hydrogen gas.
  3. 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.

    Show the answer
    Rubidium reacts even more violently than potassium, because reactivity increases further down the group.
  4. Physical properties of the halogens

    What colour is the vapour seen above iodine when it is gently warmed?

    Show the answer
    The vapour is purple.
  5. The test for chlorine, and halogens reacting with metals

    Why is blue litmus paper turning red not enough on its own to identify chlorine?

    Show the answer
    Any acidic gas turns damp blue litmus red, so only the bleaching to white confirms chlorine.

Paper 2

Rates of Reaction and Energy Changes

119 questions in the guide, across 7 subtopics. More from this topic

  1. Investigating the rate of a reaction

    Why is following loss of mass unsuitable when the gas produced is hydrogen?

    Show the answer
    Hydrogen has such a low mass that the balance shows almost no change.
  2. 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?

    Show the answer
    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.
  3. Measuring rate and interpreting rate graphs

    Suggest why a datalogger connected to a balance gives better results than reading the balance by eye.

    Show the answer
    A datalogger records readings at exactly equal intervals and does not miss a reading, so the data are more reliable.
  4. 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.

    Show the answer
    2.4 ÷ 120 = 0.02 g s⁻¹.
  5. Collision theory and factors affecting rate

    Explain why a reaction between two solids is usually extremely slow.

    Show the answer
    Only the particles at the touching surfaces can collide, so collisions are very infrequent.

Paper 2

Fuels and Earth Science

190 questions in the guide, across 12 subtopics. More from this topic

  1. Hydrocarbons and crude oil

    A compound has the formula C₃H₇Cl. State whether it is a hydrocarbon and explain your answer.

    Show the answer
    It is not a hydrocarbon because it contains chlorine in addition to carbon and hydrogen.
  2. Fractional distillation and the fractions

    Name the crude oil fraction used to surface roads and roofs.

    Show the answer
    Bitumen is used to surface roads and to cover roofs.
  3. Complete and incomplete combustion

    Write the balanced equation for the complete combustion of methane.

    Show the answer
    CH₄ + 2O₂ → CO₂ + 2H₂O.
  4. Carbon monoxide and soot

    Describe one visible sign that a gas appliance is burning its fuel incompletely.

    Show the answer
    The flame burns yellow or orange instead of blue, and black sooty marks appear around the appliance.
  5. Hydrogen and fossil fuels compared

    Explain why hydrogen is considered hazardous as a car fuel.

    Show the answer
    It is extremely flammable and forms explosive mixtures with air if it leaks.

Paper 2

Chemical Analysis, Organic Chemistry and Materials

296 questions in the guide, across 20 subtopics. More from this topic

  1. Why an ion test must be unique, and flame tests

    What flame colour is produced by a lithium ion, Li⁺?

    Show the answer
    Red.
  2. Tests for carbonate, sulfate and halide ions

    What colour precipitate does a solution containing bromide ions give with acidified silver nitrate solution?

    Show the answer
    A cream precipitate of silver bromide.
  3. Alkanes and why they are saturated

    How many covalent bonds are there in a molecule of ethane, and between which atoms?

    Show the answer
    Seven: six carbon–hydrogen bonds and one carbon–carbon bond.
  4. Reactions of alkenes, and combustion

    Explain why the complete combustion of an alkane is an oxidation reaction.

    Show the answer
    The carbon and the hydrogen in the fuel both gain oxygen, forming carbon dioxide and water.
  5. Uses of polymers, and natural polymers including DNA

    Which property of PTFE makes it useful as a non-stick coating on frying pans?

    Show the answer
    It is very unreactive and other substances do not stick to its surface.

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