Edexcel GCSE Chemistry Paper 2 Foundation June 2018 question paper 1CH0/2F

Students are investigating exothermic and endothermic reactions. They are finding the temperature change in 50 cm³ water when a solid dissolves in it. The apparatus is shown in Figure 1.

The steps needed to carry out this experiment are P, Q, R, S and T. They are shown below.

They are not in the correct order.

P pour the 50 cm³ water into the polystyrene cup Q add the solid to the water and stir R measure 50 cm³ water using a beaker S measure the initial temperature of the water T measure the final temperature of the solution when all the solid has dissolved

Write the steps in the correct order, from left to right.

The dissolving of this solid in water is an exothermic change. The experiment is repeated a number of times. Compared with the initial temperature of the water, the final temperature of the solution is

State how step R could be changed to measure the volume of water more accurately.

Figure 2 shows a cold pack.

When the pack is squeezed hard the inner bag bursts. Then the pack goes cold.

Explain why the pack goes cold.

Give the reason why the pack can be used only once.

Figure 3 shows two tests carried out on a white solid and the results of the tests.

Which ion is shown to be present by the result of test 1?

State the name of the gas given off in test 2.

State the name of the ion shown to be present in the white solid by the result of test 2.

A flame photometer can be used to measure the concentration of potassium ions in a solution.

Figure 4 shows the photometer readings for three different concentrations of potassium ions in solutions.

concentration of potassium ions in mg dm⁻³

Figure 4

A solution containing a concentration of potassium ions of 35 mg dm⁻³ is placed in the photometer. The photometer reading is 7.0.

Plot this point on the graph and then draw the straight line of best fit.

Another solution of potassium ions gives a photometer reading of 9.0.

Use the graph to find the concentration of potassium ions in this solution.

Hydrogen peroxide decomposes to form water and oxygen.

The rate of this reaction can be found by measuring the volume of oxygen formed after different time intervals.

Hydrogen peroxide solution is placed in a conical flask. The apparatus is set up as shown in Figure 5.

State the name of the piece of apparatus labelled Z in Figure 5.

At the end of the reaction the bung is removed from the conical flask. A glowing splint is put into the gas in the flask.

State what you would see.

A solid catalyst can be used for this reaction.

The experiment is repeated under identical conditions but with the catalyst added.

In the experiment with the catalyst added

decomposed is larger than when no catalyst is present

At the end of the experiment with the catalyst added, the mass of the catalyst remaining is found.

The method used to find the mass of the catalyst remaining is filter the mixture of products and catalyst determine the mass of the filter paper and solid catalyst subtract the mass of a filter paper from the mass of filter paper and solid catalyst.

This method would not give the accurate mass of catalyst remaining.

Which of the following needs to be done to give a more accurate mass?

A given mass of catalyst is more effective if it has a large surface area.

State how you could increase the surface area of some lumps of solid catalyst.

The experiment is repeated three times once using a more dilute solution of hydrogen peroxide once using a lower temperature once using a larger flask

In each case, all other conditions are kept the same.

Circle the word that shows the change in the rate of decomposition in each case.

Complete the balanced equation for the reaction and fill in the two missing state symbols.

(a) Nanoparticles are found in some sunscreens.

An atom has a radius of about 0.1 nm.

A nanoparticle might have a radius of about

A useful property of nanoparticles in sunscreens is that they

A nanoparticle has a surface area of 38 400 nm² and a volume of 51 200 nm³.

Calculate the surface area to volume ratio.

surface area to volume ratio = 1.00:_........

The molecules of three organic substances A, B and C are shown in Figure 6.

A small volume of bromine water is added to each of the substances A, B and C and the mixtures shaken. Explain why A and B decolourise bromine water but C does not.

Ethane, C₂H₆, is a hydrocarbon.

Draw a molecule of ethane showing all covalent bonds.

State why ethane is described as a hydrocarbon.

Crude oil is found in the Earth’s crust.

Which of the statements about crude oil is correct?

The substances ethane, C₂H₆, octane, C₈H₁₈, and pentadecane, C₁₅H₃₂, are all found in crude oil.

These substances

Use a word from the box to complete each of the sentences about the fractional distillation of crude oil.

Each word may be used once, more than once, or not at all.

The separation of crude oil into fractions occurs in a fractional distillation column.

Before crude oil is passed into the column it is_........ .

During the distillation, vapour rises up the column until it is cold enough for the

vapour to form a liquid. The vapour has been_........ .

Complete this sentence by underlining the correct answer in the box.

Compared with the fraction from the top of the column,

has more carbon atoms per molecule.

the fraction from the bottom of the column has a lower viscosity.

is easier to ignite.

When crude oil is separated into fractions, the amount of each fraction obtained rarely matches the demand for that fraction.

Figure 7 shows the relative amounts of four of the fractions obtained from a crude oil and the relative demand for each of these fractions.

State the fraction for which the relative amount obtained exceeds the relative demand.

In January 2015 the United Kingdom produced 850 000 barrels of crude oil per day. 45% of this crude oil was fuel oil.

Calculate the number of barrels of fuel oil present in the 850 000 barrels of crude oil.

Give your answer to two significant figures.

Figure 8 shows one molecule of each of four different substances, A, B, C and D.

substance A substance B substance C substance D

Figure 8

State the formula of a molecule of substance B.

Substance C can be formed by burning an element in oxygen.

Write the word equation for this reaction.

Consider substances A, B, and D.

Give the letters of the two substances that can be formed by burning an element in oxygen.

The amount of oxygen in the atmosphere has increased since the Earth’s early atmosphere was formed.

Explain what has caused this change.

Carbon dioxide is present in the Earth’s atmosphere.

Some processes increase the amount of carbon dioxide in the atmosphere, other processes decrease it.

Draw one straight line from each change in the amount of carbon dioxide in the atmosphere to the process causing the change.

change in the amount of
process causing the change carbon dioxide in the atmosphere

Figure 9 shows a graph of the amount of carbon dioxide in the Earth’s atmosphere from 1985 to 2005.

Describe how the amount of carbon dioxide in the Earth’s atmosphere varies within each year.

Describe the overall trend in the amount of carbon dioxide in the Earth’s atmosphere from 1985 to 2005.

Calculate the change in the amount of carbon dioxide in the Earth’s atmosphere from the beginning of 1990 to the beginning of 2000.

(a) Figure 10 shows information about a glass, a ceramic, a polymer and a metal.

*polymers soften, rather than melt, when heated.

Figure 10

Figure 11 shows part of a household wire that connects a kettle to a plug.

Figure 11

Why is this wire made of metal?

Which type of material would be most suitable for the insulation on this household wire?

Explain, using information from Figure 10, why the ceramic is a suitable material to make a cup that will contain a hot drink of tea or coffee.

The structure of a molecule of a polymer is shown in Figure 12.

Complete the structure of a molecule of the monomer used to make this polymer by adding the missing covalent bonds.

*(ii) Poly(ethene) has many uses in everyday life. Large amounts of poly(ethene) are manufactured from ethene produced by cracking fractions obtained from crude oil.

Poly(ethene) is used to make many objects. After use it is necessary to dispose of the large amounts of poly(ethene) in these objects.

Explain some of the problems associated with the manufacture and disposal of poly(ethene).

(a) A chlorine atom contains 17 electrons, 18 neutrons and 17 protons.

State the mass number of this chlorine atom.

Give the electronic configuration of this chlorine atom.

Describe what you would see if damp, blue litmus paper is placed into chlorine gas.

Chlorine exists as diatomic molecules.

In a molecule, two chlorine atoms are joined by a covalent bond.

Describe what is meant by a covalent bond.

Explain why chlorine is a gas, rather than a liquid, at room temperature.

When the gas hydrogen chloride, HC l, is dissolved in water, a solution forms. Blue litmus paper dipped in this solution turns red.

State why the litmus paper turns red.

Figure 13 lists the halogens in the order in which they appear in group 7 of the periodic table.

The melting points of four of the halogens are given.

Estimate the melting point of iodine.

Bromine reacts with heated iron.

Give the name of one halogen that would react with iron more vigorously than bromine.

Lithium, sodium and potassium are reactive metals in group 1 of the periodic table.

Sodium metal tarnishes in air to form a layer of sodium oxide on its surface. 0.92 g of sodium combined with 0.32 g of oxygen in this oxide.

Calculate the empirical formula of this sodium oxide. (relative atomic masses: O = 16, Na = 23)

You must show your working.

Sodium reacts with water to form sodium hydroxide in solution and hydrogen.

Complete the balancing of the equation for this reaction and add the state symbols for each substance.

In an experiment equal-sized pieces of lithium, sodium and potassium are added to separate samples of water.

A flame is produced only with potassium because potassium

*(ii) A teacher demonstrated this experiment.

The results are shown in Figure 14.

Describe, in detail, how the teacher would demonstrate this experiment safely, showing how the results give the order of reactivity of the metals.

Ethanol can be used as a liquid fuel.

A student investigates how much heat energy is released when a known mass of ethanol is burned.

The apparatus is set up as shown in Figure 15.

A known volume of water is placed in a metal can. The temperature of the water is measured. The ethanol is ignited and placed under the beaker so that the flame is touching the beaker. The water is heated by the flame. The flame is extinguished. The final temperature of the water is measured.

The theoretical temperature rise for burning a given mass of ethanol is 82.4 °C.

In the experiment the actual temperature rise for burning this mass of ethanol was only 34.8 °C. One reason why the temperature rise is less than expected is that the ethanol does not burn completely.

Give a reason why, even if the ethanol burns completely, the actual temperature rise is much less than the theoretical value.

Explain how the method described above could be improved to give a temperature rise closer to the theoretical value.

The amount of heat energy used to raise the temperature of the water by 34.8 °C can be calculated using

heat energy = 210 × temperature rise

Calculate the amount of heat energy used.

heat energy =_........ (energy units)

Propanol and butanol are both members of the same homologous series as ethanol.

H H H
H H H H

H H H
H H H H

propanol butanol

Propanol and butanol can also be burned in the apparatus shown in Figure 15.

Give three reasons why ethanol, propanol and butanol are members of the same homologous series.

Ethanol can oxidise when exposed to air to produce ethanoic acid and water. Propanol can also oxidise in a similar reaction when it is exposed to air.

Write the word equation for the reaction when propanol oxidises when it is exposed to air.

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