Edexcel GCSE Chemistry Paper 1 Higher November 2020 question paper 1CH0/1H

Alloys of gold are often used to make jewellery. The purity of gold is measured in carats. Different alloys of gold have different carats.

Figure 1 shows the percentage of different metals in two samples of gold.

Explain why 18 carat gold is stronger than 24 carat gold.

You may use diagrams to help your answer.

Figure 2 shows the relationship between the purity of gold in carats and the percentage of gold in the alloy.

A necklace with a mass of 5.0 g was found to contain 2.9 g of gold.

Determine the purity of the gold necklace in carats. Show your working.

purity of the gold necklace =_........ carats

A gold ring contains 3.94 g of gold.

Calculate the number of gold atoms in the ring. (relative atomic mass: Au = 197, Avogadro constant = 6.02 × 10²³)

Show your working.

Figure 3 shows the apparatus that can be used to electrolyse sodium sulfate solution using inert electrodes.

Hydrogen is produced at the negative electrode during electrolysis.

Describe the test to show the gas is hydrogen.

What is the name of gas X that forms at the positive electrode?

State what is meant by the term electrolysis.

The sodium sulfate solution was made by dissolving 28.4 g of sodium sulfate in water to make 250 cm³ of solution.

Calculate the concentration of this solution in g dm⁻³.

Give your answer to three significant figures.

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

The ions present in sodium sulfate are

Write the formula of sodium sulfate using this information.

The word equation for the reaction between copper carbonate and dilute sulfuric acid is

copper sulfuric copper carbon

Complete the balanced equation for this reaction.

Calculate the relative formula mass of copper carbonate, CuCO₃. (relative atomic masses: C = 12.0, O = 16.0, Cu = 63.5)

relative formula mass of CuCO₃ =_........

What is the chemical test to show that a gas is carbon dioxide?

Figure 4 shows a conical flask containing dilute sulfuric acid. Copper carbonate is added to the acid in the flask. The copper carbonate is added one spatula measure at a time until the reaction has finished.

State two observations that would show the reaction has finished.

The electronic configuration of carbon is 2.4 The electronic configuration of oxygen is 2.6

Draw a dot and cross diagram for a molecule of carbon dioxide.

Show outer electrons only.

Potassium hydroxide reacts with hydrochloric acid to form potassium chloride and water.

potassium hydroxide + hydrochloric acid potassium chloride + water

A student carried out a titration to find the exact volume of dilute hydrochloric acid that reacted with 25.0 cm³ of potassium hydroxide solution.

There were five steps in the titration. The steps shown are not in the correct order.

step J pour the potassium hydroxide solution into a conical flask and add a few drops of indicator to this solution step K fill a burette with the dilute hydrochloric acid and record the initial reading from the burette step L use a measuring cylinder to obtain 25 cm³ of potassium hydroxide solution step M take a final reading from the burette and calculate the volume of the dilute hydrochloric acid reacted step N run the dilute hydrochloric acid from the burette into the conical flask until the indicator changes colour

Write the steps in the correct order.

Some of the steps have been completed for you.

first step
last step

Suggest an alternative piece of apparatus that could be used in step L to obtain exactly 25.0 cm³ of potassium hydroxide solution.

A student was then asked to produce a pure sample of solid potassium chloride.

After finding the volume of acid reacted in step M, the student added this volume of acid to a fresh 25.0 cm³ sample of the potassium hydroxide solution. This mixture was then evaporated.

Explain why this new mixture was evaporated rather than the original mixture from the titration, to produce a pure sample of solid potassium chloride.

After evaporation, the mass of the potassium chloride was determined.

The theoretical yield of the experiment was 0.70 g. The actual yield was 0.84 g.

This gave a percentage yield greater than 100%.

Calculate the percentage yield of this experiment.

Suggest a reason why the actual yield was greater than the theoretical yield.

The equation for the reaction between potassium hydroxide solution and dilute hydrochloric acid is

Calculate the atom economy for the production of potassium chloride from potassium hydroxide and hydrochloric acid. (relative formula masses: KOH = 56.0, HCl = 36.5, KCl = 74.5, H₂O = 18.0)

Give your answer to one decimal place.

A sample of rock salt contains a mixture of sodium chloride and some insoluble substances.

The rock salt is added to water and the mixture stirred.

The mixture is then filtered to obtain a filtrate of sodium chloride solution.

Draw a labelled diagram of the apparatus used to filter the mixture and collect the sodium chloride solution.

Describe how a sample of pure, dry sodium chloride crystals can be obtained from the filtrate.

Inks contain coloured dyes. Samples of four inks, W, X, Y and Z, were separated using paper chromatography. Figure 5 shows the chromatogram obtained.

In the experiment, the solvent front moved 6.5 cm. Calculate the R_f value of the dye that is present in both inks X and Z.

State what could be changed in the experiment to make the R_f value more accurate.

In this experiment, ink sample Y did not move from the start line. Explain a change to the experiment that would be needed to separate the dyes in ink sample Y.

Titanium and iron are examples of transition metals.

Figure 6 shows the percentage abundance of each isotope in a sample of titanium.

Calculate the relative atomic mass of titanium in this sample.

Iron, when heated in air, reacts with oxygen to form iron oxide.

This reaction is an example of

The equipment shown in Figure 7 can be used to find the mass of oxygen that combines with iron.

Describe how the equipment shown in Figure 7 could be used to find the mass of oxygen that combines with 0.500 g of iron wool in a crucible and lid of known mass.

2.24 g of iron combines with 0.96 g of oxygen to form an oxide of iron.

Determine the formula of this oxide of iron and use it to complete the balanced equation.

(relative atomic masses: Fe = 56.0, O = 16.0)

You must show your working.

balanced equation for the reaction is

Methane reacts with steam to form hydrogen and carbon dioxide.

The reaction takes place in two stages.

Stage 1 takes in heat energy, it is endothermic.

Explain the effect of increasing the temperature on the yield of the products of stage 1.

The overall equation for the process is

0.40 g of methane were fully reacted with steam to form carbon dioxide and hydrogen.

Calculate the maximum volume of hydrogen in dm³, measured at room temperature and pressure, that could be made in this reaction.

(relative formula mass: CH₄ = 16, 1 mol of any gas at room temperature and pressure occupies 24 dm³)

*(b) Hydrogen-oxygen fuel cells can be used to provide electrical energy in a spacecraft.

The reaction that takes place in the fuel cell is

hydrogen + oxygenwater

Evaluate the advantages and disadvantages of providing electrical energy in a spacecraft using hydrogen-oxygen fuel cells rather than chemical cells.

Calcium has an atomic number of 20. A calcium atom has a mass number of 40.

Which row of the table shows the number of protons and number of neutrons in this atom of calcium?

Figure 8 shows the arrangement of electrons in an atom of calcium.

Explain, using the information in Figure 8, in which period of the periodic table calcium can be found.

Calcium and potassium react with water in similar ways.

One similarity in the reactions is that hydrogen gas is produced.

State one other similarity in the products of the reactions of calcium and potassium with water.

Potassium is higher in the reactivity series than calcium and reacts more vigorously with water than calcium reacts with water.

State why potassium is higher in the reactivity series and reacts more vigorously with water than calcium.

*(c) Calcium chloride can be prepared by the reaction of calcium with chlorine gas.

Figure 9 shows some properties of calcium, chlorine and calcium chloride.

Explain, in terms of bonding and structure, why the properties of the product, calcium chloride, are different from the properties of the reactants, calcium and chlorine.

Dilute hydrochloric acid is a strong acid.

Explain why dilute hydrochloric acid is described as a strong acid.

1 cm³ of hydrochloric acid of pH 2 is made up to a volume of 10 cm³ with distilled water.

State the pH of the new solution.

Magnesium oxide reacts with dilute hydrochloric acid to produce magnesium chloride solution and water.

Write the ionic equation for this reaction.

In an experiment magnesium hydroxide powder is added in 0.1 g portions to 25 cm³ of dilute hydrochloric acid until the magnesium hydroxide is just in excess.

Universal indicator paper can be used to test the pH of the solution after each addition of magnesium hydroxide.

Give the name of an alternative piece of equipment that can be used to measure pH.

State and explain how the pH changes as the magnesium hydroxide is added to the dilute hydrochloric acid.

Ammonia is manufactured by the Haber process.

The equation for the reaction is

The reaction is reversible and can reach equilibrium.

An iron catalyst can be used in the reaction.

Which row of the table shows how adding the iron catalyst affects the rate of attainment of equilibrium and the equilibrium yield of ammonia?

Which of the following statements is correct when the reaction reaches equilibrium?

The reaction is carried out at a pressure of 200 atmospheres.

Explain what effect a pressure higher than 200 atmospheres would have on the rate of attainment of equilibrium and on the equilibrium yield of ammonia.

Ammonium sulfate and ammonium nitrate are used as fertilisers as they both contain nitrogen, which will increase the yield of crops.

Suggest one other reason for using solid ammonium sulfate and solid ammonium nitrate as nitrogenous fertilisers.

Ammonium nitrate can be made by the reaction of ammonia with nitric acid.

Write the balanced equation for this reaction.