Edexcel GCSE Chemistry Paper 2 Higher November 2020 question paper 1CH0/2H

A chloride ion, a fluorine atom and a nanoparticle are all types of particle.

Which of the following shows the particles in order of size, starting from the smallest?

A solution, X, is thought to contain chloride, bromide or iodide ions.

The solution is tested to see whether it contains one of these ions. In the test, a few drops of two different solutions are added to X.

Name the two solutions that are added in the test.

The student carrying out the test records the following result.

Explain why the anion in X cannot be known for certain.

The metal ions in X could be identified using a flame test. There is a more sensitive and accurate instrumental method that can be used.

Give the name of an instrument that can be used to identify the metal ions in X.

An atom of potassium has atomic number 19 and mass number 39.

Give the electronic configuration of this potassium atom.

This potassium atom forms the ion K⁺.

Which row shows the number of protons and the number of neutrons in this potassium ion, K⁺?

Potassium and caesium are in the same group of the periodic table.

Explain, in terms of electrons, why potassium and caesium are in the same group.

Fluorine boils at –188C. There are forces between fluorine molecules.

Explain, in terms of these forces, why the boiling point of fluorine is low.

Potassium reacts with fluorine to form potassium fluoride. Potassium fluoride is a solid.

Complete the balanced equation for this reaction and add the state symbols.

Calcium carbonate reacts with dilute hydrochloric acid to produce carbon dioxide gas.

The rate of reaction between calcium carbonate and dilute hydrochloric acid at room temperature was investigated.

The investigation was carried out with different sized calcium carbonate pieces.

The mass of calcium carbonate and all other conditions were kept the same.

The results are shown in Figure 1.

State, using the information in Figure 1, the effect of the surface area of the calcium carbonate on the rate of this reaction.

The calcium carbonate powder produced 90 cm³ of carbon dioxide in five minutes.

Calculate the average rate of reaction in cm³s^–1.

The experiments were repeated at a higher temperature. The rate of reaction for each experiment increased.

Explain, in terms of particles, why the rate of reaction increased when the temperature was increased.

Figure 2 shows the structure of a molecule of dichloroethene.

Describe how dichloroethene monomers form a polymer.

Separate samples of dichloroethene and poly(dichloroethene) are shaken with a few drops of bromine water.

What would be seen ?

Dichloroethene is produced from ethene and chlorine.

In the overall reaction, ethene reacts with chlorine and forms dichloroethene and hydrogen chloride.

Complete the balanced equation for the overall reaction.

Poly(dichloroethene) was used to wrap food to keep it fresh.

Explain one property that a plastic food wrapping must have.

An industrial process uses 500 tonnes of dichloroethene. In the process only 96.5% of the dichloroethene molecules react.

Calculate the mass of dichloroethene that has not reacted.

Give your answer to two significant figures.

Figure 3 shows the structure of two monomers.

Monomer B contains a carboxylic acid group.

Describe what you would see when a small amount of solid sodium carbonate is added to a solution of monomer B.

When monomer A and monomer B react together they polymerise to form a polymer and one other product.

Name the type of polymerisation that takes place and name the other product.

type of polymerisation_........

name of other product_........

A naturally occurring polymer is made by combining monomers called nucleotides.

Give the name of this natural polymer.

Some polymerisation reactions produce ammonia as a waste product.

A student is given a sample of pure, dry ammonia gas.

The student suggests the following method to test for ammonia gas.

step 1 take some dry, blue litmus paper step 2 place the dry litmus paper into the dry gas step 3 observe any change in colour of the litmus paper

This test for ammonia will not work.

Give two changes that should be made to this test for it to work.

Alcohols can be dehydrated.

Complete the balanced equation for the dehydration of butan‑1‑ol by drawing the structures of the two products in the boxes. Name the two products.

Sodium thiosulfate solution, Na₂S₂O₃, reacts with dilute hydrochloric acid.

When dilute hydrochloric acid is mixed with sodium thiosulfate solution, the mixture turns cloudy.

Explain why the mixture turns cloudy.

In an investigation, different concentrations of hydrochloric acid are reacted with sodium thiosulfate solution. The mixture goes cloudy at different rates.

Describe how the rate at which the mixture goes cloudy can be measured.

You are provided with some dilute hydrochloric acid which has a concentration of 50 g dm^–3.

For this experiment, dilute hydrochloric acid with a concentration of 20 g dm^–3 is required.

How much water must be added to 100 cm³ of 50 g dm^–3 hydrochloric acid to make dilute hydrochloric acid with a concentration of 20 g dm^–3?

Sodium iodide solution is colourless.

When a solution of bromine is added to sodium iodide solution, a reaction occurs.

The mixture turns brown.

Give the name of the substance causing the brown colour.

Explain which substance has been reduced in this reaction.

Air contains several gaseous elements.

Which of these shows the three most common gaseous elements in air, listed in order from the most common to the least common?

The density of a gas can be found using the equation

A student carried out an experiment to find the density of argon.

The mass of a stopper and flask, containing no gas, was known. The flask was completely filled with argon and its mass measured.

Figure 4 shows the results the student wrote down.

Use the results to calculate the density of argon in g cm^–3.

density of argon =_........ g cm

The flask used for the experiment is shown in Figure 5. The flask holds 250.0 cm³ when filled up to the line.

There is an error in the volume the student has used in the calculation. This would give an incorrect value for the density of argon.

Identify this error and state what should be done to correct it.

what should be done to correct it_........

Four of the noble gases are argon, helium, krypton and neon.

Give these gases in order of increasing density.

Much of the carbon dioxide present in the Earth’s early atmosphere dissolved into the oceans.

This led to the formation of compounds including calcium carbonate, CaCO₃.

Some of the calcium carbonate reacted with magnesium ions to form dolomite, CaMg(CO₃)₂.

Complete the ionic equation for the reaction of calcium carbonate with magnesium ions.

dolomite

P and Q are both mixtures of gases. One has the same composition as the early atmosphere and the other has the same composition as the current atmosphere.

Tests are carried out on gas mixtures P and Q.

The test for carbon dioxide is to bubble the gas into limewater; if carbon dioxide is present calcium carbonate is formed.

The results of the tests are shown in Figure 6.

Explain, using the data in Figure 6, which gas mixture represents the early atmosphere.

The first four elements in group 1 are lithium, sodium, potassium and rubidium.

Rubidium reacts with water to form rubidium hydroxide and hydrogen.

Predict what you would see when a small piece of rubidium is placed in a large volume of water.

Why is rubidium more reactive than potassium?

8.5 g of rubidium are reacted completely with water.

The reaction makes a solution of rubidium hydroxide. The volume of this solution is 2.5 dm³.

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

(relative atomic mass: Rb = 85; relative formula mass: RbOH = 102)

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

An example of an endothermic reaction is the reaction between rubidium hydroxide and ammonium carbonate, (NH₄)₂CO₃.

This reaction forms rubidium carbonate, Rb₂CO₃, ammonia and one other product.

Write the balanced equation for this reaction.

An impure hydrocarbon fuel is burned in the apparatus in Figure 7.

When the fuel is burned

the funnel becomes hot a colourless liquid forms in tube A the indicator in tube B changes colour to show an acidic gas.

Explain these observations.

*(c) Petrol and diesel are used as fuels for cars. The emissions from three similar sized cars were investigated. The first car was the oldest, had no catalytic converter and used petrol. The other two cars were only a few years old. One of these was fitted with a catalytic converter and used petrol and the other car used diesel.

Figure 9 shows the emissions in grams for each kilometre travelled by these three cars.

Discuss and compare the impact on the environment of the emissions from these three cars using the information from Figure 9.

Figure 10 shows a flask fitted with a cotton wool plug. The flask contains an aqueous solution of a carbohydrate.

State two steps that need to be taken to turn the solution of the carbohydrate in the flask into a solution of ethanol.

The apparatus in Figure 11 is used to increase the concentration of the dilute solution of ethanol.

This apparatus did not produce a very concentrated solution of ethanol.

Describe how the apparatus can be altered to produce a more concentrated solution of ethanol.

The equation for the fermentation of a carbohydrate is

Calculate the maximum mass of carbon dioxide that could be produced if 135 g of this carbohydrate is fully fermented.

(relative formula masses: CO₂ = 44; C₆H₁₂O₆ = 180)

*(c) Figure 12 shows information about some compounds in the same homologous series.

Explain, using the data in Figure 12, why these compounds belong together in the same homologous series.