OCR GCSE Chemistry A (Gateway) Paper 2 Foundation June 2025 question paper J248/02

Butane is an alkane.

What is a use for butane?

A Ceramics

B Fertiliser

C Fuel

D Surfacing roads

A student adds sodium hydroxide to a solution containing copper ions.

Which colour precipitate is made?

A Blue

B Green

C Orange-brown

D White

Which molecule can be cracked to make octane, C₈H₁₈?

A C₆H₁₂

B C₆H₁₄

C C₈H₁₆

D C₁₂H₂₆

What is a property of a Group 1 metal?

A Brittle

B Does not conduct electricity

C Forms coloured compounds

D Low density

Magnesium reacts with excess hydrochloric acid.

What would increase the rate of the reaction?

A Use a larger volume of hydrochloric acid.

B Use a smaller beaker for the reaction.

C Use larger pieces of magnesium.

D Use more concentrated hydrochloric acid.

Which of the following formulas is for a hydrocarbon ?

A CH₂CH₂CH₂OH

B C₄H₈Cl₂

C C₆H₁₂O₆

D H₂C=CHCH₂CH₃

A solution of barium ions reacts with a solution of sulfate ions to form a white precipitate.

What is the state symbol for each species?

What are the products of the complete combustion of methane?

A Carbon and water

B Carbon, carbon monoxide, carbon dioxide and water

C Carbon dioxide and water

D Carbon monoxide and water

The alkanes have the general formula C_nH_2n+2.

What is the formula for the alkane with 7 carbon atoms?

A C₇H₁₄

B C₇H₁₆

C C₇H₁₈

D C₇H₂₀

What is a disadvantage of using a hydrogen/oxygen fuel cell instead of petrol to power a car?

A Hydrogen is a renewable resource.

B Hydrogen is difficult to store.

C The fuel cell does not produce carbon dioxide.

D The fuel cell only produces water.

The theoretical yield of a product in a reaction is 100 g.

The actual yield is 60 g.

What is the percentage yield ?

A 40%

B 60%

C 67%

D 167%

Which row in the table shows the change in the percentage of each gas in the Earth’s atmosphere today compared to the Earth’s early atmosphere?

An iron nail is left in a test tube containing water.

The iron nail rusts.

Which graph shows how the mass of the iron nail changes?

An alloy is a mixture of a metal and one or more other elements.

Brass is an example of an alloy.

Complete the sentence about brass.

Use a word from the list.

Brass is an alloy of copper and........

A 9 carat gold ring is made from a mixture of metals.

Table 16.1 shows the percentage of the different metals in the ring.

Table 16.1

Complete the bar chart by drawing the bar for copper.

The ring has a mass of 5.0 g.

Calculate the mass of gold in the ring. Use Table 16.1.

Iron can be protected from corrosion (rusting) by coating the iron with a layer of zinc.

Zinc coating

Explain how the layer of zinc acts as a barrier to protect the iron from corrosion.

Explain how the iron is protected from corrosion even if the layer of zinc is damaged.

Draw two lines to connect each metal with the correct method used to extract the metal.

Use the reactivity series.

Metal
Method used to extract

Metals can also be extracted from their metal oxide by reduction with hydrogen.

The equation shows how the metal molybdenum, Mo, is extracted using hydrogen.

Explain how the equation shows that molybdenum oxide, MoO₃, is reduced.

Calculate the atom economy for the reaction.

Use the equation:

Relative atomic mass (A_r): H = 1.0 O = 16.0 Mo = 95.9

Give your answer to 2 significant figures.

A student investigates the reactivity of four different metals, A, B, C and D.

The student adds a piece of each metal to a metal nitrate solution of each of the metals.

State one observation that would show that a reaction took place.

The table shows the student’s results.

✓ means a reaction took place ✘ means a reaction did not take place

Write the four different metals, A, B, C and D, in order of reactivity.

Explain why you placed the metals in this order of reactivity.

Copper is a transition metal.

Potassium is a Group 1 metal.

Identify two differences between copper and potassium.

Tick (✓) two boxes.

A life-cycle assessment is an analysis of the overall environmental impact that a product may have throughout its lifetime.

The life-cycle assessment is broken down into different stages.

The first stage is looking at obtaining the raw materials.

State one other stage in a life-cycle assessment.

A company does a life-cycle assessment to investigate two possible materials for making a single-use takeaway food container.

Table 18.1 gives some of the information the company uses.

Table 18.1

The company decides to use aluminium to make the food container.

Explain why using aluminium is better than using poly(propene).

Use information from Table 18.1.

Fig. 18.1 shows some reactions of propene.

Fig. 18.1

State the name of product A.

State the colour change when bromine is added to propene to make product B.

Poly(propene) is made by addition polymerisation of propene monomers.

Complete the structure of poly(propene) in the box on Fig. 18.1.

Propene reacts with hydrogen to make propane, C₃H₈.

Describe how the structure of propane is different from propene.

Use ideas about covalent bonds.

Propane........

Propene........

Table 18.2 shows the boiling points of the first four alkenes.

Table 18.2

	Boiling point (C)
Ethene	–104
Propene	– 47
Butene	– 6
Pentene	30

State what happens to the boiling point as the number of carbon atoms in the alkene increases.

In the last 75 years there has been an increase in both

• the world population

• the concentration of carbon dioxide in the atmosphere.

Why may the increase in the world population have caused the increase in the concentration of carbon dioxide in the atmosphere?

Tick (✓) one box.

A problem with an increase in the concentration of carbon dioxide is global warming.

State two problems caused by global warming.

Describe the test for carbon dioxide gas.

Test........

Result........

A student plans a titration experiment to find the concentration of a solution of sulfuric acid.

This is their method:

• Fill the burette with dilute sulfuric acid.

• Add 25.0 cm³ of 0.50 mol / dm³ sodium hydroxide solution to a conical flask.

• Add 5 drops of indicator to the sodium hydroxide solution.

• Add the dilute sulfuric acid to the sodium hydroxide solution until the indicator changes colour.

• Repeat the titration.

(a) Which piece of equipment should the student use to accurately measure the 25.0 cm³ of sodium (i) hydroxide solution?

Tick (✓) one box.

State a suitable indicator for the student to use in the titration.

Suggest an improvement to the student’s method.

The reading at the start of the rough titration is 0.0 cm³. (b)

At the end of the rough titration the student reads the volume of dilute sulfuric acid added from the burette.

What is the volume of dilute sulfuric acid added?

Give your answer to 1 decimal place.

After the rough titration the student repeats the experiment four more times.

The table shows their results.

Calculate the mean volume of dilute sulfuric acid added.

Give your answer to 2 decimal places.

Write the balanced symbol equation for the reaction between sulfuric acid, H₂SO₄, and sodium hydroxide, NaOH.

Sodium sulfate, Na₂SO₄, and water are made.

Instrumental methods of analysis can be used to analyse chemical substances.

State two advantages of instrumental methods of analysis.

Chlorine, Cl₂, reacts with lithium bromide, LiBr.

Complete the balanced symbol equation for the reaction.

Chlorine, bromine and iodine are in Group 7.

Iodine, I₂, does not react with lithium bromide.

Explain why.

A student investigates the rate of the reaction between zinc and an excess of hydrochloric acid.

The diagram shows the equipment the student uses.

The student has made a mistake setting up the delivery tube in their experiment.

Describe the mistake and the problem this will cause.

Mistake........

Problem........

The student sets up the experiment correctly.

They measure the volume of gas every 20 seconds.

The graph shows their results.

Calculate the mean rate of reaction between 0 seconds and 60 seconds.

Use the graph and the equation:

Give the units for your answer.

The student repeats the experiment.

They use the same mass of zinc, but in smaller pieces.

Draw a line on the graph to show the student’s results.

The reaction is faster when more concentrated hydrochloric acid is used.

Explain why.

Ammonia is made from nitrogen and hydrogen in the Haber process.

The word equation for the reaction is:

A catalyst is used in the Haber process.

What is the catalyst used?

Tick (✓) one box.

Explain how the catalyst speeds up the reaction.

Ammonia is used in the manufacture of fertilisers.

NPK fertilisers contain the essential elements nitrogen, phosphorus, and potassium.

The table shows the percentages of nitrogen, phosphorus, and potassium in four different fertilisers.

Plants do not grow well if they get too little of these essential elements because:

• too little nitrogen can cause yellow leaves

• too little phosphorus can cause poor root growth

• too little potassium can cause poor fruit growth.

A farmer buys a 25 kg bag of fertiliser C.

Calculate the mass of potassium in the bag of fertiliser.

Fertilisers are made in industry using a continuous process.

Fertilisers can be made in a school laboratory using a batch process.

State one advantage of using a continuous process.