OCR GCSE Chemistry B (21st Century) Paper 1 June 2018 question paper

The greenhouse effect keeps the Earth warm so that life can survive.

Carbon dioxide and water vapour are greenhouse gases.

Which gas in the list below is also a greenhouse gas?

Tick (✓) one box.

This table shows the average surface temperature increase of the Earth since 1952.

Describe how the Earth’s temperature has increased since 1952.

Roughly how many times greater was the temperature increase in 2002 compared to the temperature increase in 1962?

Tick (✓) one box.

Here is a model of a molecule of carbon dioxide.

Draw lines to link parts of this model to the correct labels.

Some of the labels are incorrect.

2 ‘Sherbet’ is a powder that fizzes on your tongue. This happens because the powder reacts with water.

Beth thinks that the reaction between sherbet and water is endothermic.

She does an experiment to find out if she is right.

Describe what she does.

What result will she get if the reaction is endothermic?

Complete the reaction profile for an endothermic reaction.

Label your diagram with these words: products, activation energy

Some farmers use manure from cows as a natural fertiliser. Other farmers use ammonium sulfate as a synthetic fertiliser.

The formula of ammonium sulfate is (NH₄)₂SO₄.

Which elements does ammonium sulfate contain?

Tick (✓) four boxes.

Plants need one of the elements in ammonium sulfate to grow faster.

Write down the name of this element.

Farmers can choose manure or ammonium sulfate as a fertiliser.

Farmers need to consider the cost of the fertiliser.

Suggest one reason, other than cost, why some farmers use manure rather than ammonium sulfate as a fertiliser.

Suggest one reason, other than cost, why some farmers use ammonium sulfate rather than manure as a fertiliser.

Alex has a solution of ammonium sulfate.

Alex uses barium chloride solution to show that the solution contains sulfate ions.

Describe what Alex sees and name the substance formed.

Alex sees........

Name of substance formed........

Alex wants to make solid ammonium sulfate from the solution of ammonium sulfate.

What would Alex do first?

Tick (✓) one box.

132 g of ammonium sulfate contain 28 g of nitrogen.

Calculate the mass of nitrogen in 1.0 kg of ammonium sulfate.

Give your answer in kg and to 2 decimal places.

Amir investigates the halogens.

Table 4.1 shows some information about the halogens.

Complete Table 4.1 by filling in the missing information.

Amir reacts some chlorine solution with a solution of potassium bromide.

The solution turns brown.

Complete word and chemical equations for the reaction that happens.

Use the equations in (b)(i) to explain why the solution turns brown.

Table 5.1 shows some data for four elements Q, R, T and X.

Which element in Table 5.1 is a metal?

Explain your answer.

Element........

Explanation........

Which element in Table 5.1 is a liquid at 500 °C?........

Which element in Table 5.1 has an atom with eight electrons in its outer shell?

Explain your answer.

Element........

Explanation........

Element T in Table 5.1 reacts with a metal to make a compound.

What type of structure does this compound have?

Tick (✓) one box.

An element has an atomic number of 16.

How many electrons are there in an atom of this element?

A factory electrolyses sodium chloride solution to make useful products.

The electrolysis produces chlorine.

The chlorine / chloride ions are attracted to the positive / negative electrode, where they lose electrons / protons.

Nina electrolyses a solution of sodium chloride.

She uses this apparatus.

Nina thinks that the experiment makes chlorine gas at one electrode.

She is not sure if the gas at the other electrode is hydrogen or oxygen.

Describe the tests Nina can do to identify chlorine, hydrogen and oxygen and the results she should expect.

Chlorine........

Hydrogen........

Oxygen........

Manganese is a metallic element. It is mixed with iron to make an alloy.

Manganese is made by heating manganese oxide with carbon.

Write a word equation for this reaction.

Aluminium cannot be made by heating aluminium oxide with carbon.

Which of the statements below are true and which are false ?

Put a tick (✓) in one box in each row.

Which model is an alloy?

Label the diagram below to describe metallic bonding.

Milk of magnesia cures indigestion.

It neutralises acid in the stomach.

Milk of magnesia is a mixture of magnesium hydroxide and water.

The formula of magnesium hydroxide is Mg(OH)₂.

Complete the equation for neutralisation.

Which medicine gives the best value for money for neutralising acid?

Kai measures the 25 cm³ of milk of magnesia using a beaker. (ii)

What could he do to measure the volume more accurately?

Tick (✓) one box.

Table 9.1 shows the properties of three polymers.

A company wants to make cups to hold boiling water.

Which polymer, A, B or C, should the company choose?

Give two reasons for your choice using the information in Table 9.1.

Which of polymers, A, B and C, has the weakest intermolecular forces?

Give a reason for your answer.

Polymer........

Reason........

Polymer A is an addition polymer.

Draw the structure of the monomer that forms polymer A.

Some fractions from crude oil are cracked to give ethene, C₂H₄.

Which homologous series is ethene a member of?

Tick (✓) one box.

Some fractions from crude oil are used as fuels.

Some fractions are used as a feedstock to make chemicals like ethene.

In the future, more crude oil will be used as a feedstock and less will be used as a fuel.

Give two reasons for this.

Compound A is a hydrocarbon in crude oil.

This equation shows the ratio of carbon atoms to hydrogen atoms in some hydrocarbons.

The empirical formula of compound A is CH₃.

Does this formula agree with the equation?

Explain your answer.

Explain why CH₃ cannot be the molecular formula of compound A.

Another hydrocarbon has a formula which fits the equation.

The formula has two carbon atoms.

Draw a fully displayed formula for this hydrocarbon.

Nanoparticles of cerium oxide, CeO₂, are added to diesel fuel.

What is the size of a nanoparticle?

Tick (✓) one box.

Cerium oxide is a very expensive solid.

The cerium oxide nanoparticles act as a catalyst. They help the fuel to burn completely so that less pollutant gases are formed.

Nanoparticles have a much higher surface area to volume ratio than solids.

Explain the advantages of using cerium oxide in the form of nanoparticles rather than as a solid.

Diesel is a fossil fuel.

Name two pollutants caused by the incomplete combustion of fossil fuels.

160 g of CeO₂ contains 30 g of oxygen.

Calculate the percentage of cerium in CeO₂.

Calcium carbonate reacts with excess hydrochloric acid to make carbon dioxide.

Here is the apparatus Jack uses to investigate the reaction.

Jack records the volume of carbon dioxide made every 200 seconds.

Here is a graph of his results.

Use the graph to calculate the rate of reaction over the first 100 s.

Rate =........ cm³ / s

Amaya wants to repeat Jack’s experiment.

She uses the same mass of calcium carbonate.

She uses the same volume and concentration of hydrochloric acid.

Which two other factors does she need to keep the same?

Jack repeats his experiment with more concentrated hydrochloric acid.

He keeps all other factors the same. The rate of reaction is faster.

Explain why.

Write about particles in your answer.

0.10 g of calcium carbonate makes 24 cm³ of carbon dioxide. (d)

Jack uses 0.070 g of calcium carbonate.

What volume of carbon dioxide does he make?

Give your answer to 2 significant figures.

Fizzy water can be found naturally.

The water is fizzy because it contains dissolved carbon dioxide gas. The carbon dioxide comes from the decomposition of rocks that contain carbonate compounds.

One compound found in rocks is magnesium carbonate.

Ali investigates the decomposition of magnesium carbonate by heating a small amount in a test tube. This is the equation for the reaction.

Ali weighs the test tube before and after heating.

The mass of the test tube after heating is less.

Ali says that this means the law of conservation of mass is not correct.

Explain why Ali is wrong.

Calculate the atom economy for the production of carbon dioxide in this reaction.

Give your answer to 1 decimal place.

In theory, 42.0 g of MgCO₃ loses 22.0 g of carbon dioxide when it completely decomposes.

Ali heats 4.2 g of MgCO₃.

Calculate the mass of carbon dioxide lost when 4.2 g of MgCO₃ completely decomposes.

In Ali’s experiment, the mass of carbon dioxide lost is 1.8 g.

Calculate the percentage yield of carbon dioxide in Ali’s experiment.

Magnesium oxide, MgO, is an ionic compound.

Draw a ‘dot and cross’ diagram for the ions in magnesium oxide.

Show the outer electron shells only.