Edexcel GCSE Chemistry, Higher tier sample questions and answers (1CH0)
Guide overview All topics Sample questions Papers and weighting Look inside Questions and answers
45 sample questions and answers
Taken from every topic of Edexcel GCSE Chemistry, Higher tier, specification 1CH0. The full guide has 1,857.
Paper 1, Paper 2
Key Concepts in Chemistry
403 questions in the guide, across 29 subtopics. More from this topic
-
Formulae, word equations and balanced equations
Give the formulae of calcium carbonate and sodium hydroxide.
Show the answer
They are CaCO₃ and NaOH. -
Protons, neutrons and electrons
What is the overall electrical charge on any atom?
Show the answer
An atom has no overall charge. -
Mendeleev's periodic table
How did Mendeleev use his table to predict elements that had not been discovered?
Show the answer
He used the properties of the elements surrounding each gap to work out what the missing element would be like. -
How ionic bonds form
What is an ion?
Show the answer
An ion is an atom, or a group of atoms, that carries a positive or a negative charge. -
Covalent bonds and molecules
Why do atoms share electrons when they form a covalent bond?
Show the answer
Sharing gives each atom a full outer shell.
Paper 1
States of Matter and Mixtures
118 questions in the guide, across 8 subtopics. More from this topic
-
The three states of matter and changes of state
Put the three states of matter in order of increasing energy of their particles.
Show the answer
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?
Show the answer
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.
Show the answer
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?
Show the answer
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.
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
271 questions in the guide, across 20 subtopics. More from this topic
-
Acids, alkalis and the pH scale
Explain why hydrogen chloride only behaves as an acid once it has dissolved in water.
Show the answer
Only in solution does it release hydrogen ions, and these ions are what make a solution acidic. -
Hydrogen ion concentration and the pH scale
The hydrogen ion concentration of a solution of pH 5 is divided by ten. Give the new pH.
Show the answer
The new pH is 6. -
Bases and alkalis
Using the definition that a base reacts with an acid to give a salt and water only, explain why a metal carbonate does not fit that definition.
Show the answer
A metal carbonate also produces carbon dioxide, so a salt and water are not the only products. -
Neutralisation and its ionic equation
Name the substance formed when hydrogen ions and hydroxide ions react together.
Show the answer
Water is formed. -
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
128 questions in the guide, across 11 subtopics. More from this topic
-
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. -
Displacement reactions as redox reactions
Write the half equation for the change undergone by magnesium atoms when magnesium displaces copper from copper(II) sulfate solution.
Show the answer
Mg → Mg²⁺ + 2e⁻. -
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. -
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. -
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.
Paper 1
Transition Metals, Quantitative Chemistry and Industrial Processes
210 questions in the guide, across 17 subtopics. More from this topic
-
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. -
Preventing rusting
Explain how storing steel tools in a sealed box with a drying agent slows rusting.
Show the answer
The drying agent removes water vapour from the air, so water is excluded from the metal surface. -
How the uses of metals relate to their properties
Explain why copper is used for electrical wiring.
Show the answer
Copper is an excellent conductor of electricity and is ductile enough to be drawn into thin wires. -
Carrying out an accurate titration
Name a suitable indicator for an acid-alkali titration and give its colour change as acid is added.
Show the answer
Phenolphthalein changes from pink to colourless. -
Atom economy and choosing a reaction pathway
Calculate the atom economy for making calcium oxide by CaCO₃ → CaO + CO₂, given relative formula masses CaO 56 and CO₂ 44.
Show the answer
The products total 100, so the atom economy is (56 ÷ 100) × 100 = 56%.
Paper 2
Groups in the Periodic Table
106 questions in the guide, across 8 subtopics. More from this topic
-
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?
Show the answer
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.
Show the answer
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.
Show the answer
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?
Show the answer
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?
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
126 questions in the guide, across 7 subtopics. More from this topic
-
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. -
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. -
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. -
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. -
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
-
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. -
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. -
Complete and incomplete combustion
Write the balanced equation for the complete combustion of methane.
Show the answer
CH₄ + 2O₂ → CO₂ + 2H₂O. -
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. -
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
305 questions in the guide, across 21 subtopics. More from this topic
-
Why an ion test must be unique, and flame tests
What flame colour is produced by a lithium ion, Li⁺?
Show the answer
Red. -
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. -
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. -
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. -
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.
Edexcel GCSE Chemistry, Higher tier Active Recall Guide
The other 1,812 questions, with the answers printed after each section.