Edexcel GCSE Chemistry Paper 1 Foundation June 2018 question paper 1CH0/1F

Figure 1 shows the dot and cross diagram for a molecule of ammonia.

What do the dots and crosses represent in the diagram?

Give the formula for the molecule of ammonia.

Ammonia can be manufactured by the Haber process.

The word equation for the reaction is

nitrogen + hydrogen ammonia

State the meaning of the symbol.

In the Haber process, the percentage yield of ammonia at equilibrium changes with temperature.

Figure 2 shows how the percentage yield of ammonia at equilibrium changes with temperature.

State what happens to the percentage yield of ammonia at equilibrium as the temperature increases.

Use the graph to find the percentage yield of ammonia at equilibrium at 450°C.

Ammonia reacts with nitric acid to form ammonium nitrate.

Complete the word equation for this reaction.

An ammonium ion has the formula NH₄⁺.

A nitrate ion has the formula NO₃^–.

Which of the following is the formula for ammonium nitrate?

Explain why farmers spread ammonium nitrate on their fields.

(a) A titration of sodium hydroxide solution with hydrochloric acid can be carried out as follows

1 a pipette is used to measure 25.00 cm³ of sodium hydroxide solution into a conical flask 2 a few drops of indicator are added to the sodium hydroxide solution 3 the burette is filled with hydrochloric acid 4 the hydrochloric acid is added to the sodium hydroxide solution until the indicator changes colour.

Describe how the pipette should be used to measure exactly 25.00 cm³ of sodium hydroxide solution into the conical flask.

The burette is first washed with water. It is then rinsed with some of the acid before it is filled with the acid to begin the titration.

Explain why the burette is rinsed with the acid.

Universal indicator solution is not a suitable indicator for an acid-alkali titration.

Give the name of an indicator that is suitable for use in the titration of sodium hydroxide solution with hydrochloric acid.

Universal indicator goes through a series of gradual colour changes as the pH changes in a solution.

Give a reason why universal indicator is not a suitable indicator to use in an acid-alkali titration.

Figure 3 shows some titration results obtained from an experiment in which an alkali is titrated with an acid.

Calculate the accurate volume of acid reacting with the alkali.

accurate volume of acid reacting_........

(a) Atoms contain electrons, neutrons and protons.

Draw one line to link each particle to its correct relative charge.

Which of the following is the relative mass of a proton?

Argon is in group 0 of the periodic table.

Identify, using the periodic table on the back cover of this paper, which of these elements is in the same period as argon.

Figure 4 shows the atomic number and mass number of two isotopes of argon.

Describe the structure of an atom of argon-38 and of an atom of argon-40.

The molecular formula of butene is C₄H₈.

Which of the following is the empirical formula of butene?

Calculate the relative formula mass of butene, C₄H₈.

(relative atomic masses: H = 1, C = 12)

relative formula mass_........

When burnt completely in air, butene forms carbon dioxide and water.

Balance the equation for this reaction by putting numbers in the spaces provided.

Describe the test to show that a gas is carbon dioxide.

Substance X is a gas at room temperature. It is a simple molecular, covalent substance.

Which row of the table shows the properties that substance X is most likely to have?

Diamond has a giant covalent structure.

State one property of diamond that is the result of its giant covalent structure.

Two compounds of barium are barium sulfide and barium chloride.

The hazard symbol shown in Figure 5 is on bottles containing barium metal.

State the meaning of this hazard symbol.

Give the names of the elements combined in barium sulfide.

Barium chloride is toxic.

Explain one safety precaution that should be taken when using barium chloride.

A beaker of barium chloride solution and a beaker of dilute sulfuric acid were placed on a balance, as shown in Figure 6.

The total mass reading on the balance was 25.7 g.

The dilute sulfuric acid was poured into the barium chloride solution and the beaker replaced on the balance, as shown in Figure 7.

Figure 7

The mixture formed contained a white precipitate.

State the total mass reading on the balance after the reaction.

Give the name of the white precipitate formed by the reaction of barium chloride solution with dilute sulfuric acid.

Solid sodium chloride is dissolved in water.

The sodium chloride solution is electrolysed in the apparatus shown in Figure 8.

State why sodium chloride solution, rather than solid sodium chloride, must be used in this experiment.

The formulae of the ions present in the sodium chloride solution are

Circle the ions that would be attracted to the anode.

Molten lead bromide can be electrolysed to form molten lead and bromine gas.

Explain how a student could modify the apparatus shown in Figure 8 to carry out this electrolysis.

An ink is a mixture of coloured substances dissolved in water.

Which method is used to separate the coloured substances in the ink?

The apparatus shown in Figure 9 can be used to separate water from ink.

Cold water flows through the condenser.

On Figure 9 use arrows to show where the water should flow in and where it should flow out.

Explain why a condenser is used.

The flask was heated with a Bunsen burner.

Give the name of an alternative piece of apparatus that could be used to heat the flask.

The particles in the ink in the flask can be shown as in Figure 10.

In the boxes below, draw the arrangement of particles that would be expected at A and B shown in Figure 9.

Changes of state between the three states of matter are shown in Figure 11.

The changes shown are physical changes.

Explain why these changes are called physical changes rather than chemical changes.

7 *(a) Pure metals are often converted into more useful alloys. For example, aluminium is converted into an alloy used in aircraft, iron is converted into an alloy used in cutlery and gold alloys are used in jewellery. These processes of alloying change the structures of the metals.

Some properties of pure aluminium, iron and gold are shown in Figure 12.

Explain how alloying changes these pure metals to make the alloys more suitable for the given uses.

Iron objects can corrode when exposed to the atmosphere.

Corrosion involves the oxidation of iron.

State what is meant by oxidation.

Painting iron objects prevents corrosion.

Explain why painting iron objects prevents corrosion.

Corrosion of iron objects can be prevented by painting them or by electroplating them.

State one other way of preventing the corrosion of iron objects.

The apparatus shown in Figure 13 was used to electroplate a spoon with nickel.

State to what the anode and cathode have to be connected in order to carry out the electroplating.

Predict the name of a substance that could be dissolved in water to form the electrolyte for this electroplating.

State two characteristic properties of metals.

Acids are used to make salts.

Give the name of the acid used to make chlorides.

Salts of metals can be prepared by reacting the metal with an acid to produce the salt and hydrogen.

Describe the test to show that the gas is hydrogen.

Nickel is a metal.

Explain how the structure of a nickel atom, Ni, changes when it forms a nickel ion, Ni²⁺

A nickel sulfate solution is made by dissolving 23.5 g of nickel sulfate to make 250 cm³ of solution.

Calculate the concentration of the solution in g dm^–3.

concentration =_........ g dm

Excess solid nickel carbonate is added to dilute sulfuric acid in a beaker.

nickel sulfuric nickel carbon

Nickel sulfate is formed in solution.

Describe how a sample of pure, dry nickel sulfate crystals can be obtained from the mixture of nickel sulfate solution and excess solid nickel carbonate in the beaker.

Most metals are extracted from ores found in the Earth’s crust.

The method used to extract a metal from its ore is linked to the reactivity of the metal.

Part of the reactivity series is shown in Figure 14.

Iron ore contains iron oxide.

Iron is extracted from iron oxide by heating the oxide with carbon.

iron carbon

In this reaction

The formula of the iron oxide is Fe₂O₃.

Calculate the maximum mass of iron that can be obtained from 240 tonnes of iron oxide, Fe₂O₃.

(relative atomic masses: O = 16, Fe = 56)

mass of iron =_........ tonnes

Aluminium cannot be extracted by heating its oxide with carbon. Aluminium has to be extracted from its oxide by electrolysis.

Explain why.

Predict the method that will have to be used to extract calcium from its ore.

*(d) Aluminium is extracted from its ore by electrolysis. Iron is extracted from its ore by heating with carbon. Both metals can also be obtained by recycling.

Explain the advantages of recycling aluminium and iron rather than extracting them from their ores.

(a) Hydrogen burns in air at a temperature well above 100 °C to form water.

The boiling points of hydrogen and water are shown in Figure 15.

Use this information to add the missing state symbols to the equation for the reaction taking place as the hydrogen burns.

The atom economy for the reaction in (i) is 100%.

State how the equation shows that the atom economy is 100%.

Lead can be obtained by heating its oxide with carbon. The balanced equation for the reaction is

Calculate the atom economy for the production of lead in this reaction. (relative atomic masses: C = 12, O = 16, Pb = 207 relative formula masses: PbO = 223, CO₂ = 44)

Give your answer to two significant figures.

In an experiment to produce lead, 7.67 g of lead are obtained. The theoretical yield of lead for the experiment is 11.80 g.

Calculate the percentage yield of lead in this experiment.

In most reactions, the percentage yield of any product is less than 100%.

Give two reasons why the percentage yield is less than 100%.