OCR GCSE Chemistry A (Gateway) Paper 2 Foundation June 2023 question paper J248/02

1h 45m 90 marks

23 questions

Report a problem

Question

What is wrong?

Text or a picture is cut off or split Something on the paper is not here The text does not read properly The marks are wrong Something else

Goes to whoever maintains the question split. No account needed and nothing is published on this page.

A student does a flame test with a sample of potassium chloride.

Which colour is the flame?

A Lilac

B Green‑blue

C Red

D Yellow

$Question 1, shown as an image$

[1]

Answer

What is the test for chlorine gas?

A Damp universal indicator paper turns red then white

B Decolourises bromine water

C Limewater turns milky

D Relights a glowing splint

$Question 2, shown as an image$

[1]

Answer

Why do marble chips react faster with warm hydrochloric acid than with cold hydrochloric acid?

A The warm hydrochloric acid acts as a catalyst.

B The warm hydrochloric acid has more crowded particles.

C The warm hydrochloric acid has particles with more energy.

D The warm hydrochloric acid has particles that move slower.

$Question 3, shown as an image$

[1]

Answer

Which conditions are needed for the rusting of iron to happen?

A Air and no water

B Air and oil

C Air and salt

D Air and water

$Question 4, shown as an image$

[1]

Answer

What is the displayed formula of ethanol ?

$Question 5, shown as an image$

[1]

Answer

Tap water is treated to make it safe to drink.

Which substance is added to the tap water to kill bacteria and microbes?

A Aluminium sulfate

B Carbon dioxide

C Chlorine

D Iodine

$Question 6, shown as an image$

[1]

Answer

Methane is a hydrocarbon.

Which substance cannot be produced when methane burns in air?

A Carbon

B Carbon dioxide

C Hydrogen

D Water

$Question 7, shown as an image$

[1]

Answer

Brass is an alloy used to make musical instruments.

What are the main metals in brass?

A Aluminium and copper

B Copper and tin

C Copper and zinc

D Lead and tin

$Question 8, shown as an image$

[1]

Answer

What was the main gas in the Earth’s early atmosphere?

A Ammonia

B Carbon dioxide

C Nitrogen

D Oxygen

$Question 9, shown as an image$

[1]

Answer

Bromine reacts with sodium iodide.

What is the balanced symbol equation for the reaction?

$Question 10, shown as an image$

[1]

Answer

Ammonia is made in the Haber process.

$Question 11, shown as an image$

What happens when this reaction reaches equilibrium?

A The backward reaction happens at a faster rate than the forward reaction.

B The forward and backward reactions happen at the same rate.

C The forward and backward reactions stop happening.

D The forward reaction happens at a faster rate than the backwards reaction.

$Question 11, shown as an image$

[1]

Answer

Iron objects can be protected from rusting by coating them with a layer of zinc.

What is this process called?

A Galvanising

B Insulating

C Oxidation

D Reduction

$Question 12, shown as an image$

[1]

Answer

Calcium carbonate, CaCO₃, thermally decomposes to make calcium oxide, CaO, and carbon dioxide.

$Question 13, shown as an image$

5.0 g of calcium carbonate makes 2.8 g of calcium oxide.

How much carbon dioxide is made?

A 2.2 g

B 2.8 g

C 4.4 g

D 7.8 g

$Question 13, shown as an image$

[1]

Answer

Crude oil is a resource that is being made extremely slowly.

Which word describes a resource that is being made extremely slowly?

A Finite

B Hydrocarbon

C Non‑renewable

D Petrochemical

$Question 14, shown as an image$

[1]

Answer

The Group 7 element fluorine is a gas at room temperature and pressure.

The Group 7 elements show a trend in boiling points going down the group.

Which row shows the boiling points of the Group 7 elements?

		Boiling Point (	C)
	Fluorine	Chlorine	Bromine	Iodine
A	–188	59	184	–15
B	–188	–34	59	184
C	188	184	59	–15
D	–15	184	188	59

$Question 15, shown as an image$

[1]

Answer

(a)

The teacher says that the reaction is faster with magnesium powder than with magnesium ribbon.

Use the results to explain why the teacher is correct.

[2]

Answer

(b)(i)

Describe how the rate of reaction changes when the concentration of the hydrochloric acid increases.

[1]

Answer

(b)(ii)

Explain your answer to (i) using ideas about particles.

[2]

Answer

(c)

The teacher used 0.1 g of magnesium.

0.1 g of magnesium reacts with hydrochloric acid to make 0.008 g of hydrogen gas.

A student suggests that the rate of reaction could be investigated by measuring the loss in mass during the reaction.

Suggest why this method would not work well.

[1]

Answer

(d)

Describe the test for hydrogen gas.

[2]

Answer

(e)

In another experiment, the teacher reacts 0.1 g of zinc with excess hydrochloric acid.

$Question 16, shown as an image$

Calculate the mass of hydrogen gas made.

Relative atomic mass (A_r): H = 1.0 Zn = 65.4

[3]

Answer

The table shows information about the physical properties of four elements, W, X, Y and Z.

	W	X	Y	Z
Density (g / cm³)	0.97	7.87	0.003	1.74
Melting point (C)	98	1538	–102	650
Conducts electricity?	✓	✓	✗	✓

(a)

Which element is a non‑metal?

Give a reason for your answer.

Element........

Reason........

[2]

Answer

(b)

One of the elements is sodium in Group 1.

Which element is sodium?

Give a reason for your answer.

Element........

Reason........

[2]

Answer

(c)

One of the elements is a transition metal.

(c)(i)

Compare the physical and chemical properties of Group 1 metals and transition metals. Use the information in the table, and your own knowledge.

[3]

Answer

(c)(ii)

Transition metals can be used as catalysts.

What is meant by a catalyst?

[2]

Answer

(d)

[2]

Answer

(e)

Iron reacts with dilute sulfuric acid, H₂SO₄.

Iron sulfate, FeSO₄, and hydrogen gas, H₂, are made.

(e)(i)

Write the balanced symbol equation for this reaction.

[1]

Answer

(e)(ii)

A student reacts 2.8 g of iron with dilute sulfuric acid.

The student makes 5.4 g of iron sulfate.

They predicted that they should have made 7.6 g of iron sulfate.

Calculate their percentage yield.

Give your answer to 1 decimal place.

[3]

Answer

Propane, C₃H₈, is an alkane.

Propane undergoes complete combustion in oxygen. Carbon dioxide and water are made.

(a)

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

[2]

Answer

(b)

The table shows the energy given out when 1 g of different alkanes burn.

Alkane	Number of carbon atoms	Energy given out (kJ)
methane	1	55.6
ethane	2	52.6
propane	3	50.4
butane	4
pentane	5	48.7
hexane	6	48.4

(b)(i)

Plot a graph of the data from the table.

[2]

Answer

(b)(ii)

Draw a curve of best fit on your graph.

[1]

Answer

(b)(iii)

The energy given out when 1 g of butane burns is missing from the table.

Use the graph to estimate the energy given out by butane.

[1]

Answer

(b)(iv)

What name is given to the type of reaction that gives out energy ?

[1]

Answer

(c)

Complete the displayed formula of propane, C₃H₈.

[1]

Answer

(d)

Combustion of alkanes makes carbon dioxide gas.

(d)(i)

State an environmental problem caused by increased levels of carbon dioxide gas.

[1]

Answer

(d)(ii)

Explain how this environmental problem can be reduced.

[1]

Answer

A student plans a titration experiment.

The diagram shows some of the apparatus they use.

(a)

[4]

Answer

(b)

This is the equation for the reaction in the experiment.

$Question 19, shown as an image$

(b)(i)

What type of reaction is this?

Tick (✓) one box.

$Question 19, shown as an image$

[1]

Answer

(b)(ii)

Water is a waste product in this reaction.

Calculate the atom economy for the reaction.

Relative atomic mass (A_r): H = 1.0 O = 16.0 Na = 23.0 Cl = 35.5

[3]

Answer

Crude oil is separated into different fractions by fractional distillation.

Table 20.1 shows information about three of the molecules that are found in three different fractions.

Table 20.1

Molecule	Formula	Boiling point (C)
nonane	C₉H₂₀	151
heptadecane	C₁₇H₃₆	302
octacosane	C₂₈H₅₈	436

(a)

Which of these three molecules would be separated highest up the fractionating column?

Explain your answer using ideas about molecular size and boiling point.

Molecule........

Reason........

[3]

Answer

(b)

Cracking breaks down large molecules produced in fractional distillation into more useful molecules.

The equation shows the cracking of octacosane.

$Question 20, shown as an image$

octacosane dodecane molecule X

(b)(i)

State the name of molecule X, C₂H₄.

[1]

Answer

(b)(ii)

Molecule X has the general formula C_nH_2n.

Octacosane and dodecane are both alkanes and have a different general formula.

State the general formula of the alkanes.

[1]

Answer

(c)

Table 20.2 shows the percentage supply and percentage demand for some of the different fractions obtained from crude oil.

Table 20.2

Fraction	Percentage supply (%)	Percentage demand (%)
LPG	2	4
petrol	5	23
naphtha	8
kerosene	12	7
diesel oil	17	23
fuel oil	56	38

(c)(i)

Calculate the percentage demand for naphtha.

[1]

Answer

(c)(ii)

Suggest why fuel oil, rather than diesel oil, is cracked to obtain petrol.

[1]

Answer

[6]

Answer

A student investigates two solutions, A and B.

They know that

• one solution contains a halide ion

• the other solution contains a different anion.

They test 2 cm³ of each solution for the halide ion using this method:

• Add a few drops of dilute hydrochloric acid and shake.

• Add a few drops of silver nitrate solution.

• Record the colour of the precipitate.

(a)

The teacher says that the student should have used a different acid instead of dilute hydrochloric acid.

(a)(i)

State the name of the acid the student should have used.

[1]

Answer

(a)(ii)

Explain why using dilute hydrochloric acid would affect the results of this test.

[2]

Answer

(b)

[2]

Answer

(c)

[3]

Answer

(d)

Barium chloride solid is toxic if swallowed and harmful if inhaled.

Barium chloride solutions with concentrations of 21 g / dm³ are suitable for experiments in school.

Calculate the mass of barium chloride that should be dissolved in 25 cm³ of water to make a solution with a concentration of 21 g / dm³.

Use the equation:

$Question 22, shown as an image$

Give your answer to 2 significant figures.

[3]

Answer

The table shows information about three different polymers, A, B and C.

Tensile strength is the amount of load a material can take before it breaks.

	Melting point (C)	Softening temperature (C)	Stiffness (MPa)	Tensile strength (MPa)
A	130	72	980	15
B	240	95	3200	65
C	250	75	2400	50

(a)

A company wants to use a polymer to make a disposable cup for hot drinks.

Suggest and explain which polymer, A, B or C, the company should use.

Polymer........

Reason........

[3]

Answer

(b)

This is the repeating unit in polymer B.

Draw the structure of the monomer from which polymer B is made.

[2]

Answer

(c)

Some substances are naturally occurring polymers.

Draw lines to connect each monomer with its naturally occurring polymer.

[2]

Answer

The paper as printed

Spotted a mistake on this page?Report a problem

OCR J248 · Paper 2

Question 1

Question 2

Question 3

Question 4

Question 5

Question 6

Question 7

Question 8

Question 9

Question 10

Question 11

Question 12

Question 13

Question 14

Question 15

Question 16

Question 17

Question 18

Question 19

Question 20

Question 21

Question 22

Question 23