OCR GCSE Combined Science A (Gateway) Chemistry Paper 4 Foundation June 2022 question paper J250/04

Supplies of crude oil are running out.

Which word describes crude oil?

A Finite

B Renewable

C Reusable

D Sustainable

A student heats four different metals using a Bunsen burner.

The table shows their observations.

What is the order of reactivity of the metals from most reactive to least reactive ?

A W, X, Z, Y

B W, Z, X, Y

C Y, X, Z, W

D Z, Y, W, X

Nitrogen, N₂, reacts with hydrogen, H₂, to make ammonia, NH₃.

What is the name of this type of reaction?

A Combustion

B Electrolysis

C Neutralisation

D Reversible

Which toxic gas is produced from burning fossil fuels?

A Carbon dioxide

B Carbon monoxide

C Nitrogen

D Oxygen

Alkanes are hydrocarbons with the formula C_nH_2n+2.

Which compound is an alkane?

A C₆H₈

B C₇H₁₂

C C₈H₁₆

D C₉H₂₀

A student has four different solids.

• One of the solids is a catalyst.

• The student tests 1 g of each solid in a chemical reaction.

The table shows the student’s observations for each solid.

Which solid is the catalyst?

In the UK, one person produces about 9.5 × 10³ kg of carbon dioxide per year. 10

One tree can take in 15 kg of carbon dioxide per year.

Approximately how many of these trees are needed to reduce one person’s yearly carbon dioxide output to zero?

A 15

B 650

C 1600

D 140 000

What produced the gases present in the Earth’s early atmosphere?

Tick (✓) one box.

What is the percentage of oxygen in the Earth’s atmosphere today ?

The amounts of carbon dioxide and water vapour in the Earth’s early atmosphere decreased over time.

Draw lines to connect each gas with the correct description of how it decreased over time

The Earth’s atmosphere today contains gases from Group 0 in the Periodic Table.

The table shows the amounts of the gases from Group 0 in the Earth’s atmosphere

The total amount of the gases from Group 0 is 0.938%.

Complete the table by calculating the exact amount of krypton in the Earth’s atmosphere today.

Write your answer in the box in the table.

What is a property of the Group 0 gases?

Tick (✓) one box.

The student writes the word equation for the reaction.

Complete the word equation for the reaction.

Why does this reaction happen?

Use the reactivity series in Fig. 12.1.

Use the reactivity series in Fig. 12.1 to answer parts (b), (c) and (d).

Another student repeats the experiment but places a different metal in the solution of copper sulfate.

There is no chemical reaction.

Suggest a metal that this student used.

Name one metal that can be extracted by heating its oxide with carbon.

Name one metal that can be extracted from its oxide by electrolysis but not by heating its oxide with carbon.

Complete the sentence below to explain the difference in the reactivity of sodium and lithium.

Use one of the words.

electrons neutrons protons

Sodium atoms lose........ more easily than lithium atoms.

State the trend in reactivity of the Group 1 metals.

Name a Group 1 metal which is more reactive than sodium.

Drinking water that comes from lakes and reservoirs must be made safe to drink.

Which name is given to water that has been made safe to drink?

Tick (✓) one box.

Water can also be purified by simple distillation.

The diagram shows the equipment used by a student to distil sea water.

Give two reasons why this equipment is not suitable to produce water on a large scale.

On average one person in the UK uses 149 litres of water every day.

Only 3% of this water is used for drinking.

Calculate the amount of drinking water a family of four uses every day.

Give your answer to 3 significant figures.

Amount of drinking water =........ litres

The processing of crude oil by the petrochemical industry can be shown by different experiments.

Fig. 14.1 shows an experiment where paraffin is turned into decane and gas X.

Fig. 14.1

Fig. 14.2 shows the reaction of paraffin, C₁₄H₃₀, to make decane, C₁₀H₂₂, and gas X.

Fig. 14.2

Complete the sentences below to describe the experiment.

The experiment is called cracking / displacement / distillation.

It is an example of combustion / reduction / thermal decomposition.

The porous pot in Fig. 14.1 acts as a catalyst in the reaction.

What effect does the porous pot have on the rate of the reaction ?

decreases it
increases it
no effect

What effect does the porous pot have on the activation energy of the reaction?

decreases it
increases it
no effect

Use Fig. 14.2 to answer these questions.

Write the formula of gas X.

Describe what happens to a molecule of paraffin as it turns into a molecule of decane.

15* Carrier bags can be made from either recycled paper or biodegradable plastic (which will decay and break down when in the ground).

Figs 15.1 to 15.4 show information about the production of carrier bags from recycled paper and from biodegradable plastic.

Fig. 15.1
Fig. 15.2

Fig. 15.3
Fig. 15.4

Suggest whether the carrier bags should be made from recycled paper or biodegradable plastic.

Explain your choice using the information from Figs 15.1 to 15.4 and your own scientific knowledge.

This question is about the Group 7 elements.

Table 16.1 shows some information about the Group 7 elements.

Table 16.1

Complete the table by predicting the appearance of astatine at room temperature.

Write your answer in the box in Table 16.1.

The sizes of the molecules are measured in picometres (pm).

What is the size of a fluorine molecule in metres (m)?

Tick (✓) one box.

Use Table 16.1 to complete the x axis and plot a line graph of the boiling points of fluorine, chlorine, iodine and astatine against the size of their molecules.

Draw a line of best fit.

Use your graph to predict the boiling point of bromine.

Table 16.1 is repeated below.

Table 16.1

A student thinks that fluorine molecules have the weakest intermolecular forces.

Give two reasons why they are correct.

Use data from Table 16.1.

Describe one similarity and one difference in the arrangement of electrons in atoms of fluorine and chlorine.

Similarity........

Difference........