OCR GCSE Chemistry A (Gateway) Paper 4 Higher November 2021 question paper J248/04

Butane is a hydrocarbon molecule with a low boiling point.

Which statement about butane is correct?

A Butane is a large molecule and has strong intermolecular forces.

B Butane is a large molecule and has weak intermolecular forces.

C Butane is a small molecule and has strong intermolecular forces.

D Butane is a small molecule and has weak intermolecular forces.

Lumps of zinc react with dilute sulfuric acid.

What change would decrease the rate of this reaction?

A Further diluting the sulfuric acid with water.

B Using a larger volume of sulfuric acid.

C Using warmer sulfuric acid.

D Using zinc powder instead of zinc lumps.

The Earth’s early atmosphere formed 4.5 billion years ago.

Which process produced the gases in the Earth’s early atmosphere?

A Combustion

B Condensation

C Photosynthesis

D Volcanic activity

What are the conditions usually used for the production of ammonia in the Haber process?

A 200 °C, 450 atmospheres pressure and an iron catalyst

B 450 °C, 2 atmospheres pressure and a vanadium(V) oxide catalyst

C 450 °C, 200 atmospheres pressure and an iron catalyst

D 450 °C, 200 atmospheres pressure and a nickel catalyst

A scientist predicts that they should make 96 tonnes of product in a reaction.

They only actually make 81 tonnes of product.

What is the percentage yield ?

A 15%

B 19%

C 84%

D 119%

When iron rusts it forms hydrated iron(III) oxide.

What happens to iron in this reaction?

A Iron is decomposed.

B Iron is neutralised.

C Iron is oxidised.

D Iron is reduced.

The concentration of a solution of sodium hydroxide, NaOH, is 0.725 mol / dm³. 7

What is the concentration of this solution in g / dm³?

(The relative atomic mass, A_r, of H is 1.0, of Na is 23.0 and of O is 16.0).

0.018 g / dm³ A

29.0 g / dm³ B

55.2 g / dm³ C

725.0 g / dm³ D

What is the formula of the functional group in carboxylic acids ?

A –C=C–

B –COOH

C –CO₂

D –OH

What is the balanced half equation for the formation of bromine from bromide ions?

Metals can be extracted by biological methods.

Plants absorb metals through their roots and concentrate them in their cells.

What is this method of metal extraction called?

A Bioleaching

B Carbon capture

C Organic extraction

D Phytoextraction

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

Which graph shows the effect of the concentration of the dilute hydrochloric acid on the reaction

Which of these functional groups can react together to form a condensation polymer?

A –C=C– and –COOH

B –C=C– and –NH₂

C –COOH and –NH₂

D –OH and –NH₂

An alcohol and a carboxylic acid react to form an ester and water in an equilibrium reaction.

Why is an acid catalyst used in this reaction?

A The catalyst is changed chemically during the reaction.

B The equilibrium concentration of the ester is increased.

C The purity of the ester is increased.

D The time taken to reach equilibrium is decreased.

Sacrificial protection is a method used to prevent iron from rusting.

Sacrificial protection involves plating the iron with a more reactive metal such as zinc.

Which statement explains how sacrificial protection works?

A The more reactive metal gains electrons more easily than the iron.

B The more reactive metal is less readily oxidised than the iron.

C The more reactive metal is more readily reduced than the iron.

D The more reactive metal loses electrons more easily than the iron.

Explain how the mass spectrum and the infrared spectrum show that the sample is ethanol, C₂H₅OH.

Mass spectrometry and infrared spectrometry are both examples of instrumental methods of analysis.

Describe two advantages of instrumental methods of analysis.

Ethanol, C₂H₅OH, burns in a plentiful supply of oxygen to form carbon dioxide and water.

This is an example of complete combustion.

Write the balanced symbol equation for this reaction.

If there is a limited supply of oxygen, incomplete combustion will happen.

Describe a disadvantage of incomplete combustion.

Ethanol, C₂H₅OH, can be dehydrated to make ethene, C₂H₄.

Calculate the atom economy for the production of ethene from ethanol.

(The relative formula mass, M_r, of C₂H₅OH is 46.0 and of C₂H₄ is 28.0).

A car manufacturer is designing a new car. They need to decide if the car will have a petrol engine or a diesel engine.

The car manufacturer carries out a life-cycle assessment for both types of car.

Describe the purpose of a life-cycle assessment.

Describe two examples of data, other than waste products and pollution, that could be included in a life-cycle assessment.

At which stage are the most oxides of nitrogen produced by the diesel car ?

Tick (✓) one box.

The car manufacturer estimates that a petrol car produces 29.8 tonnes of carbon dioxide over its lifetime.

A diesel car produces only 20.5 tonnes of carbon dioxide over its lifetime.

Use the graphs to calculate the mass, in tonnes, of carbon dioxide produced by the petrol car and the diesel car during vehicle operation.

Use your answers to calculate the difference, in tonnes, in the mass of carbon dioxide produced by the petrol car and the diesel car during vehicle operation.

Give your final answer to 2 significant figures.

Mass of carbon dioxide produced by the petrol car =........ tonnes

Mass of carbon dioxide produced by the diesel car =........ tonnes

Difference in mass of carbon dioxide =........ tonnes

A student investigates the rate of reaction between large marble chips and dilute hydrochloric acid.

The student measures the volume of carbon dioxide gas given off every 30 seconds.

Look at the apparatus they use.

State how the student can improve their experiment to measure the volume of carbon dioxide more accurately.

The graph shows the student’s results.

The student has drawn a tangent to the line on the graph at 60 seconds.

Use the tangent to calculate the rate of reaction at 60 seconds.

Rate of reaction =........ cm³ / s

The student repeats the experiment. The only difference is they use smaller marble chips.

Draw a line on the graph to show the results of this experiment.

The balanced equation for this reaction is:

In their experiment the student reacted 0.5 mol of dilute hydrochloric acid, HC l, with 0.5 mol of marble chips, CaCO₃.

Use the equation to show that, in this experiment, the calcium carbonate is in excess.

This question is about elements in Group 7 of the Periodic Table.

The table shows some properties of Group 7 elements.

Complete the table. Use ideas about trends down Group 7.

Chlorine reacts with sodium bromide, NaBr, in a displacement reaction.

Write the balanced symbol equation for this reaction.

Explain, in terms of the arrangement of electrons, the decrease in reactivity from fluorine to astatine.

Iron reacts with chlorine to form iron chloride.

Look at the equation for the reaction.

Calculate the mass of iron chloride that can be made from 2.80 g of iron.

Give your answer to 3 significant figures.

(The relative atomic mass, A_r, of Cl is 35.5 and of Fe is 55.8).

The fractional distillation of crude oil makes many useful fractions.

Table 20.1 shows the boiling temperatures of some fractions.

Look at the diagram of a fractionating column.

Complete the diagram by writing the names of the missing fractions in the boxes.

Choose from the fractions in Table 20.1.

Use the boiling temperatures in the table to help you.

After crude oil is separated into fractions, some fractions are then cracked.

Explain why some fractions are cracked.

Complete the balanced symbol equation for the cracking of a molecule of C₃₀H₆₂.

Explain why compound B decolourises bromine water but compound A does not.

This question is about polymers.

Many biological substances are polymers.

Complete the table to state the type of monomer which forms each of the biological polymers.

Look at the structure of the polymer called poly(styrene).

This polymer is made from a monomer.

Draw the structure of the monomer.

Polyesters are also polymers.

Look at the structure of a polyester.

This polymer is made from two different monomers.

Draw a molecule of each different monomer.

Nylon is another polymer.

The chemicals used to make nylon are corrosive. Cyclohexane is highly flammable.

Describe and explain two precautions a teacher should take to carry out this experiment safely.

A company makes hydrogen iodide, H I, gas by reacting hydrogen gas with iodine gas.

Look at the equation for the reaction.

What is the volume of hydrogen gas, in dm³, needed to react with 150 dm³ iodine at (a) (i) room temperature and pressure?

Use the balanced symbol equation to help you.

Calculate the volume of hydrogen iodide formed, in dm³, when 150 dm³ of iodine (ii) completely reacts with hydrogen at room temperature and pressure.

Use the balanced symbol equation to help you.

The reaction to make hydrogen iodide is an equilibrium reaction.

The forward reaction is exothermic.

The yield of hydrogen iodide and the rate at which the reaction reaches equilibrium are affected by different conditions.

Look at two possible reaction conditions, A and B, the company could use for this reaction.

The company decides to use reaction conditions A, instead of B.

Explain why they make this choice.

Use ideas about rate of reaction and position of equilibrium to help you.

A student investigates an ionic compound, Y, to identify the two different ions in the compound.

The table shows the results of the tests that the student does.

Use the results of tests 1 and 2 to write the formula of compound Y.

Another ionic compound, Z, also contains two ions.

Describe how the student could improve the test in part (ii) to confirm that the anion compound Z is a chloride ion, Cl^–.