OCR GCSE Chemistry A (Gateway) Paper 2 Foundation June 2019 question paper J248/02

Which type of water is potable water?

A Groundwater

B Seawater

C Tap water

D Waste water

Which of these elements is a transition metal ?

A Calcium

B Caesium

C Carbon

D Cobalt

Lithium, sodium and potassium all react with water.

In all three reactions the same gas is produced.

What is the name of the gas?

A Carbon dioxide

B Chlorine

C Hydrogen

D Oxygen

The rate of a reaction can be changed by adding a catalyst to the reaction mixture.

Which line of the table shows how the rate of reaction and the mass of the catalyst change as

How was the Earth’s early atmosphere formed?

A Animals breathing

B Global warming

C Plants growing

D Volcanic activity

Crude oil is a mixture of hydrocarbons.

Crude oil is separated into useful fractions.

Which of these mixtures of substances could be in a fraction from crude oil?

A C₂H₄, C₄H₁₀, C₄H₁₀O

B C₂H₄, C₂H₃Br, C₄H₁₀

C C₂H₆, C₃H₈, C₄H₁₀

D C₂H₆, C₂H₃Br, C₄H₁₀O

Crude oil is separated into useful fractions by fractional distillation.

The diagram shows the useful fractions made in fractional distillation.

Which of these fractions has the weakest intermolecular forces?

A Bitumen

B Diesel oil

C Gases

D Petrol

What type of reaction takes place between an alkene and hydrogen?

A Addition

B Dehydration

C Neutralisation

D Thermal decomposition

The table shows the main stages in the life-cycle assessment of a manufactured product.

What is the correct order for the stages?

A 1, 2, 3, 4

B 1, 2, 4, 3

C 2, 1, 4, 3

D 2, 4, 1, 3

The Haber process is used to make ammonia, NH₃.

What is the raw material for the nitrogen?

A Air

B Hydrochloric acid

C Natural gas

D Seawater

Which statement describes the test for chlorine gas ?

A A lighted splint makes a squeaky pop.

B Limewater turns milky.

C A glowing splint re-lights.

D Damp litmus paper is bleached.

Which statement describes the atom economy of a reaction?

A A measure of how many atoms in the reactants form the waste products.

B A measure of how many atoms in the reactants form the desired product.

C A measure of the actual yield of product compared to the predicted yield of product.

D A measure of how many atoms form waste products compared to desired products.

Which statement describes the properties of transition metals ?

A High melting point, shiny when freshly cut and brittle.

B Good conductors of electricity, low density and low melting point.

C Good conductors of electricity, strong and malleable.

D Strong, malleable and low density.

Which statement describes the advantages of instrumental methods of analysis?

A Instruments can analyse very small amounts and carry out the analyses slowly.

B Instruments are very accurate and use large amounts of substances.

C Instruments are very accurate and carry out the analyses slowly.

D Instruments are very accurate and can run all the time.

The table shows the composition of the Earth’s early atmosphere compared with the atmosphere today.

Which gas has changed by the largest percentage from the early atmosphere to the atmosphere today?

A Nitrogen

B Oxygen

C Argon

D Carbon dioxide

This question is about the corrosion of metals.

A student investigates the rusting of iron.

Fig. 16.1 shows the experiments she sets up.

Write about what the student would observe in each tube after one week.

Explain the observations.

Tube A........

Tube B........

Tube C........

Another student buys a new bicycle. The bicycle chain is made of iron.

The student decides to oil the chain to prevent it from rusting, as shown in Fig. 16.2.

Explain why oiling the chain will prevent the iron from rusting.

A galvanised iron bucket is made of iron coated with a layer of zinc.

After years of use, the zinc coating has become scratched.

The iron below the zinc has been exposed but the iron has not rusted.

Explain why the iron has not rusted.

This question is about hydrocarbons.

The table shows some information about alkanes.

Complete the table.

Ethane is a saturated hydrocarbon.

Explain why ethane is called both a hydrocarbon and saturated.

A student has two test tubes. One contains ethane and one contains ethene.

The student added bromine water to each test tube.

Describe what she observes.

Ethane........

Ethene........

Ethane belongs to the homologous series called the alkanes.

What is the name of the homologous series that ethene belongs to?

Pentane, C₅H₁₂, is an alkane found in petrol.

Pentane undergoes complete combustion in excess oxygen, O₂.

Carbon dioxide and water are made.

Write the balanced symbol equation for the complete combustion of pentane.

This question is about the extraction of metals.

When iron oxide is heated with carbon, iron is made.

Complete the word equation for this reaction.

Iron oxide is reduced during this reaction.

Explain how you can tell that iron oxide is reduced.

Zinc is usually extracted from zinc oxide by heating zinc oxide with carbon.

Explain why. Use the reactivity series to help you.

Aluminium is extracted from aluminium oxide by electrolysis.

Explain why. Use the reactivity series to help you.

The table shows some information about aluminium and zinc.

Suggest two reasons why it could be more important to recycle zinc than aluminium.

Use information from the table to help you.

Aluminium alloys are often used to build aircraft.

A sample of an aluminium alloy contains 1.28 g of magnesium and 43.70 g of aluminium only.

Calculate the percentage of magnesium in this alloy.

Give your answer to 3 significant figures.

The Haber process is used to make ammonia, NH₃.

The reaction reaches a dynamic equilibrium.

What happens to the rate of the forward and backward reactions at dynamic equilibrium?

What happens to the concentrations of the reacting substances at equilibrium?

Ammonia is used to make fertilisers.

Fertilisers usually contain nitrogen.

Name the two other elements that fertilisers usually contain.

Ammonium sulfate is a salt used as a fertiliser.

Ammonium sulfate can be made in a laboratory in a batch process.

Ammonia solution is titrated with dilute sulfuric acid to make a solution of ammonium sulfate, as shown in the diagram.

Describe how you would make dry crystals of ammonium sulfate from ammonium sulfate solution.

Calcium sulfate is another salt.

A student made some calcium sulfate.

Look at the method he used:

• pour 100 cm³ of calcium nitrate solution into a beaker

• add drops of sodium sulfate solution until a precipitate appears

• allow the precipitate to settle to the bottom of the beaker

• pour off the liquid

• use a spatula to transfer the solid calcium sulfate onto a piece of filter paper.

Describe and explain two ways that the student could improve his method to increase amount of pure, dry calcium sulfate made.

Crude oil is separated into useful fractions using fractional distillation.

The table shows the percentages of crude oil fractions from different oil wells.

Which oil well contains the highest percentage of low boiling point fractions?

Tick (✓) one box.

A barrel of crude oil from oil well Y has a mass of 139 kg.

Calculate the mass of fuel oil in this barrel.

Fractions from crude oil contain alkanes.

Alkanes have the general formula C_nH_2n+2.

Write the formula of hexadecane, the alkane with 16 carbon atoms.

A sample of decane was cracked.

Look at the diagram of the apparatus used.

Describe how this apparatus is used to produce ethene from decane.

One molecule of decane, C₁₀H₂₂, produced two molecules of ethene, C₂H₄, and one molecule of product Z.

Write the formula for product Z.

A student investigates the reaction between magnesium and dilute hydrochloric acid, HC l.

The student adds magnesium ribbon to hydrochloric acid in a beaker, as shown in the diagram.

Magnesium chloride, MgCl₂, and hydrogen gas are made.

Write the balanced symbol equation for this reaction.

The student repeats experiment 1. This time he uses acid at a lower temperature.

Explain, using the reacting particle model, what happens to the rate of reaction and predict the reaction time for this reaction.

During chemical reactions, reactants are used up and the rate of reaction decreases.

Explain, in terms of particles, why the rate of reaction decreases.

This question is about properties of materials.

Police bullet-resistant vests could be made from steel or Kevlar ®.

The table shows some information about steel and Kevlar^®.

Describe and explain two reasons why bullet-resistant vests are made from Kevlar^® instead of steel.

What type of molecule is Kevlar ® ?

Nanoparticles are being used to make a material that is better than Kevlar^® at resisting bullets.

Nanoparticles are often made of silicon dioxide.

A silicon dioxide nanoparticle has a diameter of 18 nm.

The diameter of a silicon atom is 0.22 nm.

Estimate how many times larger the silicon dioxide nanoparticle is, compared to a silicon atom.

Give your answer to 1 significant figure.

Silicon dioxide is used as a catalyst.

Suggest why 1 g of silicon dioxide is more effective as a catalyst when used as nanoparticles rather than as a powder.

Evaluate the information shown in the graph.

To what extent does the graph support a link between human activity and global warming?

There are problems with using information about CO₂ emissions by fossil fuels to draw conclusions about the effect of carbon dioxide emissions on global sea levels.

Suggest what these problems are.

Describe one effect on the Earth’s climate of increased carbon dioxide levels, other than rising sea levels.

Suggest how we can lower carbon dioxide levels.