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13+ · Chemistry

CE.S-C1 Chemistry: Materials

ISEB CE ISEB CE 13+ Science (Chemistry) · Calculator allowed · about 60 minutes

Total Marks

Name: _______________________________ Date: ____ / ____ / ______

Answer ALL questions. Show all your working.

Materials can change from one state to another. The table below lists four changes of state.

(a)State the name of the change of state when a liquid changes into a gas at its boiling point.(1)

(b)State the name of the change of state when a gas changes into a liquid.(1)

(c)State the name of the change of state when a solid changes into a liquid.(1)

(d)State the name of the change of state when a liquid changes into a solid.(1)

(Total for Question 1 is 4 marks)

A pupil looks at three samples under a microscope, labelled X, Y and Z. Diagram X shows particles arranged in a fixed, regular pattern, touching each other. Diagram Y shows particles that are close together but arranged randomly and can move past one another. Diagram Z shows particles that are far apart and moving quickly in random directions.

(a)Which diagram, X, Y or Z, represents a sample of ice?(1)

(b)Which diagram, X, Y or Z, represents a sample of steam?(1)

(c)Explain, in terms of particles, why a gas can be compressed (squashed into a smaller volume) much more easily than a liquid.(2)

(Total for Question 2 is 4 marks)

A jeweller has a small block of clear glass. The block has a mass of 25 g and a volume of 10 cm^3.

(a)Calculate the density of the glass. Use the equation: density = mass / volume.(2)

(b)The density of water is 1.0 g/cm^3. State, with a reason, whether the glass block would float or sink in water.(1)

(Total for Question 3 is 3 marks)

Materials are chosen for particular jobs because of their properties. For each item below, name ONE suitable material and give ONE property of that material that makes it suitable for the job.

(a)A saucepan base.(1)

(b)A rain coat.(1)

(c)The casing of an electrical plug.(1)

(d)A bicycle helmet.(1)

(e)A window pane.(1)

(Total for Question 4 is 5 marks)

A group of pupils collect a sample of water from a rock pool at Lyme Regis. The water contains sand and dissolved salt.

(a)Name the technique the pupils should use to remove the sand from the salt water.(1)

(b)Name the technique the pupils could use to obtain solid salt crystals from the salt water once the sand has been removed.(1)

(c)Explain why the salt water should be heated gently and evaporation stopped just before the last of the water has boiled away, rather than heating until the dish is completely dry.(2)

(d)Name a technique that could be used to separate the different coloured dyes in a sample of food colouring.(1)

(Total for Question 5 is 5 marks)

A pupil heats a solid substance from -10C and records its temperature every two minutes. Some of her results are shown in the table below.
Time (min): 0, 2, 4, 6, 8, 10, 12
Temperature (C): -10, 0, 0, 0, 10, 20, 30

(a)Use the data to state the melting point of the substance.(1)

(b)Explain, in terms of energy and particles, why the temperature stays constant between 2 and 6 minutes even though the substance is still being heated.(3)

(c)Predict the temperature of the substance at 14 minutes if it continues to be heated at the same rate.(2)

(Total for Question 6 is 6 marks)

A technician tests four metal rods, copper, iron, zinc and tin, to compare how well they conduct electricity, using identical circuits each containing a rod, a battery, a bulb and an ammeter.

(a)Name TWO variables that should be kept the same in this investigation to make it a fair test.(2)

(b)State the piece of equipment used to measure the current in each circuit.(1)

(c)The results showed that copper allowed the largest current to flow. State what this tells you about the electrical conductivity of copper compared with the other three metals.(1)

(d)Define what is meant by the term malleable.(1)

(Total for Question 7 is 5 marks)

A pupil investigates how the temperature of water affects the mass of sugar that will dissolve in 100 cm³ of water. She adds sugar to the water a small amount at a time, stirring, until no more will dissolve, and repeats this at five different temperatures.

(a)Identify the independent variable in this investigation.(1)

(b)Identify the dependent variable in this investigation.(1)

(c)Give ONE variable that should be controlled (kept the same) each time.(1)

(d)The pupil's results showed that more sugar dissolved at higher temperatures. Suggest ONE way she could improve the precision of her results.(2)

(Total for Question 8 is 5 marks)

A pupil wants to find the density of a small, irregularly shaped metal block. She uses a measuring cylinder containing 40 cm³ of water. When the metal block is lowered into the cylinder, the water level rises to 60 cm^3. The mass of the block is 158 g.

(a)Calculate the volume of the metal block.(2)

(b)Calculate the density of the metal block. Give your answer to 2 significant figures.(2)

(c)The table shows the densities of four metals: aluminium 2.7 g/cm³, iron 7.9 g/cm³, copper 8.9 g/cm³, lead 11.3 g/cm^3. Use your answer to (b) to identify the metal in the block.(1)

(Total for Question 9 is 5 marks)

Four building materials, granite, slate, marble and chalk, are tested for hardness using a relative hardness scale from 1 (very soft) to 10 (very hard). The results are shown in the table.
Material: Granite, Slate, Marble, Chalk
Relative hardness: 7, 4, 3, 1

(a)Use the table to identify which material is the hardest.(1)

(b)A fingernail has a relative hardness of about 2.5 on this scale. Use the table to identify which material would be easiest to scratch with a fingernail.(1)

(c)A builder wants to use one of these materials for a kitchen worktop that will have knives and hot pans placed on it. Using the data, suggest which material would be most suitable, and explain your reasoning.(3)

(Total for Question 10 is 5 marks)

A pupil investigates the rusting of iron nails using four test tubes, each containing one iron nail.
Tube 1: nail in dry air only (no water).
Tube 2: nail in boiled water with a layer of oil on top to keep air out.
Tube 3: nail in water with air present.
Tube 4: nail in water with air present, with a piece of magnesium ribbon attached to the nail.
After one week she records whether each nail has rusted.

(a)State the two substances that are needed for iron to rust.(2)

(b)Using the results from tubes 1, 2 and 3, explain what conclusion the pupil can draw about the conditions needed for rusting.(2)

(c)In tube 4, the nail with magnesium ribbon attached does not rust. Suggest why.(1)

(Total for Question 11 is 5 marks)

Reinforced concrete is a composite material made from concrete with steel rods or mesh set inside it. It is widely used to build bridges and multi-storey car parks.

(a)State what is meant by a composite material.(1)

(b)Concrete is strong when squashed (in compression) but weak when stretched (in tension). Steel is strong in tension. Explain why combining concrete and steel produces a better building material than using concrete alone.(3)

(Total for Question 12 is 4 marks)

Rods of four different metals, copper, aluminium, iron and lead, all the same length and thickness, each have a small ball attached to one end with wax. The other end of each rod is heated at the same time using an identical flame. A stopwatch records the time taken for each ball to fall off as the wax melts. The results are shown in the table.
Metal: Copper, Aluminium, Iron, Lead
Time for ball to fall (s): 45, 68, 120, 150

(a)State which metal is the best conductor of thermal (heat) energy, and explain your reasoning using the data.(2)

(b)Suggest ONE variable, other than the length and thickness of the rods, that must be controlled to make this a fair test.(1)

(c)A pupil suggests that lead is the worst conductor of heat because it has a low melting point. Evaluate this suggestion.(3)

(Total for Question 13 is 6 marks)

A model boat is made from aluminium (density 2.7 g/cm³) shaped into a hollow hull. The boat has a mass of 135 g and floats in water, displacing 150 cm³ of water.

(a)Calculate the average (overall) density of the boat.(2)

(b)The density of water is 1.0 g/cm^3. Explain why the boat floats even though aluminium itself is denser than water.(4)

(Total for Question 14 is 6 marks)

A forensic scientist uses paper chromatography to compare an ink sample from a suspect pen with three reference inks. A pencil line is drawn near the bottom of the chromatography paper and a spot of the ink is placed on it. The paper is placed in a beaker with a shallow layer of solvent, below the pencil line. After the solvent has risen up the paper, the solvent front has travelled 8.0 cm from the pencil line, and one dye spot from the suspect's ink has travelled 5.2 cm.

(a)Calculate the Rf value of this dye spot. Use the equation: Rf = distance travelled by dye / distance travelled by solvent. Give your answer to 2 decimal places.(2)

(b)The table shows the Rf values of dyes in three reference inks: ink P = 0.65, ink Q = 0.40, ink R = 0.82. Using your answer to (a), state which reference ink most likely matches the dye in the suspect's ink.(1)

(c)Explain why a pencil line, rather than a pen or ink line, is used to mark the starting position of the sample.(2)

(Total for Question 15 is 5 marks)

Brass is an alloy made by mixing copper and zinc. A jeweller makes 250 g of brass using copper and zinc in the ratio 7:3 by mass.

(a)Calculate the mass of copper used.(2)

(b)Calculate the mass of zinc used.(1)

(c)Explain why brass (an alloy) is harder than pure copper.(2)

(Total for Question 16 is 5 marks)

A pupil wraps three identical beakers, each containing 100 cm³ of water at 80C, in wool, cotton and polyester respectively, and measures the temperature of the water every 2 minutes for 20 minutes. The polyester-wrapped beaker was placed on a windowsill in direct sunlight, while the other two beakers were placed on a bench away from the window.

(a)Identify one way in which this investigation is not a fair test.(1)

(b)Explain how this problem could affect the pupil's conclusion about which fabric is the best insulator.(1)

(c)Suggest TWO improvements the pupil could make to her method.(2)

(Total for Question 17 is 4 marks)

An engineer is choosing a material to build the main support beams of a footbridge over a river. She is considering three materials: mild steel, reinforced concrete and carbon-fibre composite. Discuss which material would be the most suitable, using ideas about the properties of materials (such as strength, stiffness, density, cost and resistance to corrosion) to support your answer.

(Total for Question 18 is 6 marks)

Plastics (polymers) are classified as either thermosoftening or thermosetting.

(a)State what happens to a thermosoftening polymer when it is heated strongly.(1)

(b)State what happens to a thermosetting polymer when it is heated strongly, after it has already been moulded and set.(1)

(c)Explain, in terms of the bonding between polymer chains, why thermosetting polymers do not melt when reheated.(2)

(d)A saucepan handle is made from a thermosetting polymer rather than a thermosoftening one. Suggest why.(1)

(Total for Question 19 is 5 marks)

The density of pure gold is 19.3 g/cm^3.

(a)Rearrange the density equation (density = mass / volume) to make volume the subject.(1)

(b)A gold bar has a mass of 965 g. Calculate the volume of the gold bar.(2)

(c)A jeweller suspects a 'gold' ring is not pure gold. The ring has a mass of 15.44 g and a volume of 1.1 cm^3. Calculate the density of the ring and use it to determine whether the ring is likely to be pure gold.(3)

(Total for Question 20 is 6 marks)

Mark scheme · CE.S-C1 Chemistry: Materials

Question 1

(a) B1 boiling, oe (accept vaporising)
(a) Answer: Boiling
(b) B1 condensation/condensing, cao
(b) Answer: Condensation
(c) B1 melting, cao
(c) Answer: Melting
(d) B1 freezing, cao
(d) Answer: Freezing

Question 2

(a) B1 X, cao
(a) Answer: X
(b) B1 Z, cao
(b) Answer: Z
(c) B1 in a gas the particles are far apart, with large spaces between them, oe
(c) B1 in a liquid the particles are already close together (touching), so there is very little space left to reduce, oe
(c) Answer: A gas has large spaces between its particles that can be reduced when squashed; a liquid's particles are already close together, so there is almost no space left to squash out.

Question 3

(a) M1 correct substitution, 25 / 10
(a) A1 2.5 g/cm³, cao
(a) Answer: 2.5 g/cm³
(b) B1 sink, because the density of the glass (2.5 g/cm³, ft) is greater than the density of water (1.0 g/cm³)
(b) Answer: Sink, because its density (2.5 g/cm³) is greater than the density of water (1.0 g/cm³).

Question 4

(a) B1 any sensible metal (e.g. copper, aluminium, stainless steel) with a correctly matched property, e.g. good conductor of thermal energy/heat, oe
(a) Answer: Example: copper or aluminium, because it is a good conductor of heat.
(b) B1 a polymer/plastic (e.g. polyester, PVC, nylon) with correctly matched property, e.g. waterproof and flexible, oe
(b) Answer: Example: a polymer such as polyester or PVC, because it is waterproof and flexible.
(c) B1 a thermosetting polymer (e.g. Bakelite/melamine) with correctly matched property, e.g. electrical insulator and does not melt when warm, oe
(c) Answer: Example: a thermosetting polymer, because it is an electrical insulator and does not soften or melt if it gets warm.
(d) B1 expanded polystyrene/foam or a composite shell with correctly matched property, e.g. low density and absorbs impact, oe
(d) Answer: Example: expanded polystyrene foam, because it has a low density and absorbs the energy of an impact.
(e) B1 glass with correctly matched property, e.g. transparent and rigid, oe
(e) Answer: Example: glass, because it is transparent (lets light through) and rigid.

Question 5

(a) B1 filtration, cao
(a) Answer: Filtration
(b) B1 evaporation/crystallisation, cao
(b) Answer: Evaporation (crystallisation)
(c) B1 stopping while some solution remains and letting it cool slowly allows large, well-formed crystals to grow, oe
(c) B1 heating right until completely dry can make the salt spit/decompose, or only produce small crystals, oe
(c) Answer: Stopping just before dryness and allowing slow cooling gives large, well-formed crystals; heating to complete dryness can cause spitting and only produces small crystals.
(d) B1 (paper) chromatography, cao
(d) Answer: Chromatography

Question 6

(a) B1 0 (degrees C), cao
(a) Answer: 0C
(b) B1 the energy supplied is being used to break/weaken the forces (bonds) holding the particles in their fixed positions, oe
(b) B1 not to increase the kinetic energy/speed of the particles, so the temperature does not rise, oe
(b) B1 once all the solid has melted into a liquid, the energy supplied increases the particles' kinetic energy again, so the temperature rises, oe
(b) Answer: The energy is used to break the forces between particles (melting) rather than to speed the particles up, so the temperature does not rise until melting is complete.
(c) M1 identify the rate of temperature increase after melting is complete, e.g. +10C per 2 minutes from the pattern 10, 20, 30
(c) A1 40 (degrees C), ft from their identified rate
(c) Answer: 40C

Question 7

(a) B1 any one of: length of rod / thickness (diameter) of rod / voltage of the battery or power supply / temperature of the rods
(a) B1 a second, different correct variable from the list above
(a) Answer: Any two of: length of rod, thickness of rod, voltage of the power supply, temperature of the rods.
(b) B1 ammeter, cao
(b) Answer: Ammeter
(c) B1 copper is the best (most electrically conductive) of the four metals tested, oe
(c) Answer: Copper is the best electrical conductor of the four metals.
(d) B1 can be hammered, bent or pressed into shape without breaking/cracking, oe
(d) Answer: Able to be hammered or pressed into shape without breaking.

Question 8

(a) B1 temperature (of the water), cao
(a) Answer: The temperature of the water
(b) B1 the mass of sugar that dissolves, cao
(b) Answer: The mass of sugar that dissolves
(c) B1 any one of: volume of water (100 cm³) / rate or speed of stirring / type of sugar used
(c) Answer: Example: the volume of water (100 cm³).
(d) B1 repeat each temperature reading (at least twice more) and calculate a mean mass of sugar dissolved, oe
(d) B1 use a more precise/sensitive balance, or add the sugar in smaller amounts each time, oe
(d) Answer: Repeat each temperature at least three times and take a mean, and use a more sensitive balance/add sugar in smaller amounts.

Question 9

(a) M1 60 - 40
(a) A1 20 cm³, cao
(a) Answer: 20 cm³
(b) M1 158 / their (a)
(b) A1 7.9 g/cm³, ft from (a)
(b) Answer: 7.9 g/cm³
(c) B1 iron, ft from (b)
(c) Answer: Iron

Question 10

(a) B1 granite, cao
(a) Answer: Granite
(b) B1 chalk, cao
(b) Answer: Chalk
(c) B1 granite (or slate), ft a sensible choice supported by the data
(c) B1 it has the highest hardness value of the materials given, so it is more resistant to being scratched by knives, oe, ft
(c) B1 any further valid linked reasoning, e.g. a harder material is also generally more resistant to wear and to damage from hot pans, oe
(c) Answer: Granite, because it has the highest relative hardness (7), making it most resistant to scratching by knives and general wear.

Question 11

(a) B1 water/moisture
(a) B1 oxygen/air
(a) Answer: Water (moisture) and oxygen (air)
(b) B1 tube 1 (air only, no water) does not rust and tube 2 (water only, air excluded) does not rust, but tube 3 (both water and air present) does rust, oe
(b) B1 therefore both water and oxygen (air) must be present together for iron to rust, oe
(b) Answer: Neither air alone nor water alone (with air excluded) causes rusting, but both together (tube 3) do, showing that both water and oxygen are needed for rusting.
(c) B1 magnesium is more reactive than iron, so it reacts/corrodes in preference to (instead of) the iron, protecting the iron from rusting (sacrificial protection), oe
(c) Answer: Magnesium is more reactive than iron, so it corrodes instead of the iron, protecting the nail (sacrificial protection).

Question 12

(a) B1 a material made from two (or more) different materials combined together, giving properties different from (or better than) the individual materials, oe
(a) Answer: A material made by combining two or more different materials so that it has different, improved properties from either material alone.
(b) B1 the steel provides the tensile strength that plain concrete lacks, oe
(b) B1 so the reinforced concrete can withstand both compressive and tensile (or bending) forces, oe
(b) B1 this makes structures such as bridges less likely to crack or fail under load, oe
(b) Answer: The steel adds the tensile strength that concrete lacks, so the combined material resists both compression and tension/bending, making structures such as bridges much less likely to crack or fail.

Question 13

(a) B1 copper, cao
(a) B1 its ball fell off in the shortest time (45 s), showing that heat energy travelled along the copper rod fastest, oe
(a) Answer: Copper, because its wax ball fell off in the shortest time (45 s), showing heat travelled through it fastest.
(b) B1 any one of: amount/size of wax used, distance of the ball from the flame, size/type of flame used, size of ball used
(b) Answer: Example: the amount of wax used to attach each ball.
(c) B1 the low melting point of lead is not relevant here, because it is the wax that melts, not the lead rod itself; the rod's own melting point is never reached, oe
(c) B1 lead's rate of thermal conduction (how quickly heat energy passes through its particles) is simply lower than that of the other three metals, oe
(c) B1 the pupil's suggestion confuses melting point with thermal conductivity, which are two different properties, oe
(c) Answer: The suggestion is not correct: the rod itself never melts (only the wax does), so its melting point is irrelevant. Lead is simply a poorer thermal conductor than the other metals; the pupil has confused melting point with thermal conductivity.

Question 14

(a) M1 135 / 150
(a) A1 0.9 g/cm³, cao
(a) Answer: 0.9 g/cm³
(b) B1 the hull shape spreads the aluminium out over a large volume, most of which is occupied by air (the hollow space) rather than solid metal, oe
(b) B1 this gives the boat as a whole (aluminium and trapped air together) an average/overall density that is lower than solid aluminium's density, oe
(b) B1 an object floats in a liquid when its average density is less than the density of that liquid, oe
(b) B1 the calculated average density in (a), 0.9 g/cm³, ft, is indeed less than the density of water (1.0 g/cm³), which is why the boat floats, ft
(b) Answer: The hollow shape spreads the aluminium over a large volume filled mostly with air, so the boat's average density (0.9 g/cm³) is lower than solid aluminium's and lower than water's (1.0 g/cm³), so it floats.

Question 15

(a) M1 correct substitution, 5.2 / 8.0
(a) A1 0.65, cao
(a) Answer: 0.65
(b) B1 ink P, ft from (a)
(b) Answer: Ink P
(c) B1 pencil (graphite) is insoluble in the solvent, so it does not dissolve or move up the paper and does not mix with the ink spot being tested, oe
(c) B1 a pen/ink line could dissolve in the solvent and travel up the paper, contaminating the results and making the dye spots harder to see or measure accurately, oe
(c) Answer: Pencil is insoluble in the solvent so it stays put and does not interfere with the sample, whereas an ink line would dissolve and move up the paper, contaminating the results.

Question 16

(a) M1 250 / 10 x 7, or equivalent method to find one part and scale up
(a) A1 175 g, cao
(a) Answer: 175 g
(b) B1 75 g, ft: 250 - their (a)
(b) Answer: 75 g
(c) B1 zinc atoms are a different size from copper atoms, so they distort the regular layers of atoms in the copper, oe
(c) B1 this disrupts the layers sliding over each other easily, making the alloy harder than the pure metal, oe
(c) Answer: The different-sized zinc atoms distort the regular layers of copper atoms, stopping the layers sliding over each other easily, so brass is harder than pure copper.

Question 17

(a) B1 the polyester beaker was exposed to different surrounding conditions (sunlight/warmth through the window) compared with the other two beakers, oe
(a) Answer: The polyester beaker was in direct sunlight while the others were not, so the surrounding conditions were not the same for all three.
(b) B1 the polyester beaker might appear to cool more slowly (seem to insulate better) simply because of the extra warmth from the sunlight, not because polyester is actually the best insulator, oe
(b) Answer: The sunlight could keep the polyester beaker's water warmer than it otherwise would be, making polyester seem like a better insulator than it really is.
(c) B1 place all three beakers in the same location, away from direct sunlight or draughts, oe
(c) B1 use the same starting temperature for each and take repeat readings/use a data logger to calculate a mean at each time, oe
(c) Answer: Place all three beakers in the same location away from sunlight/draughts, and repeat each measurement (or use a data logger) to calculate a mean at each time.

Question 18

Level 1 (1-2): Basic, isolated statements about one material or one property, with little or no comparison between materials. Limited use of scientific vocabulary.
Level 2 (3-4): Some relevant properties of at least two materials are described and linked to the choice of material, with a basic comparison and a conclusion, though the reasoning may be incomplete or not fully justified.
Level 3 (5-6): A clear, well-reasoned discussion comparing the properties (e.g. strength, stiffness, density, cost, corrosion resistance) of at least two, ideally all three, materials, leading to a justified conclusion about the most suitable material for the footbridge, using accurate scientific vocabulary throughout.
Indicative content:
- Mild steel: very strong in tension and compression, and stiff, but is dense (heavy) and can corrode (rust) if not protected/painted regularly, which adds to maintenance cost.
- Reinforced concrete: strong in compression and, with steel reinforcement, reasonably strong in tension too; it is cheap and durable, but very dense (heavy), and beams may need to be bulky.
- Carbon-fibre composite: very strong and stiff for its low weight (low density), and does not corrode, giving low maintenance, but it is much more expensive to produce than steel or concrete.
- A balanced conclusion might recommend steel or reinforced concrete for a low-cost, standard footbridge, or carbon-fibre composite where light weight and low maintenance are prioritised and cost is less important.
- Credit any other relevant, correctly explained property (e.g. ease of shaping, sustainability/recyclability, expected lifespan) used to support a justified conclusion.

Question 19

(a) B1 it softens/melts (and can be reshaped, then cooled to set again), oe
(a) Answer: It softens or melts, and can be reshaped before cooling to set again.
(b) B1 it does not melt or soften; it keeps its shape (or chars/burns) rather than becoming liquid, oe
(b) Answer: It does not melt or soften; it keeps its rigid shape (or chars/burns) instead of turning liquid.
(c) B1 thermosetting polymers have strong covalent bonds (cross-links) formed between the polymer chains, oe
(c) B1 these cross-links hold the chains firmly together in a rigid network, so heating cannot free the chains to move/flow as a liquid, oe
(c) Answer: Strong covalent cross-links join the polymer chains together in a rigid network, and heating does not provide enough energy to break these cross-links, so the chains cannot move freely and the material does not melt.
(d) B1 it will not melt or soften when it gets hot near a hob/oven, so it remains rigid and safe to hold, oe
(d) Answer: It will not melt or soften when heated, so it stays rigid and safe to grip even when near a hot hob or oven.

Question 20

(a) B1 volume = mass / density, cao
(a) Answer: volume = mass / density
(b) M1 965 / 19.3
(b) A1 50 cm³, cao
(b) Answer: 50 cm³
(c) M1 15.44 / 1.1
(c) A1 14.0 g/cm³, cao (awrt 14.0)
(c) B1 the ring is unlikely to be pure gold, because 14.0 g/cm³ is much lower than the density of pure gold (19.3 g/cm³), ft from their density
(c) Answer: 14.0 g/cm³; the ring is unlikely to be pure gold, since its density is much lower than 19.3 g/cm^3.

Chemistry: Materials - Worksheets, Questions and Revision