Ceramics, polymers & composites

Crisp packets are often made from poly(propene) coated with a thin layer of aluminium on the inside.

Poly(propene) is a polymer made from the monomer propene, CH₂CHCH₃.

What is the relative formula mass of propene?

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

Describe how monomer molecules combine to make polymers.

Crisps go stale when exposed to the atmosphere.

In an experiment some crisp packets were made from aluminium, some from poly(propene) and some from poly(propene) coated with aluminium. These packets were tested.

Figure 15 shows the results.

Low porosity is an advantage of using poly(propene) coated with aluminium as it prevents the crisps from becoming damp.

Explain, using Figure 15, one other advantage of using poly(propene) coated with aluminium.

The aluminium coating can be replaced by a very thin layer of material called a nanosheet.

The nanosheet is made from amino acids and is less than 100 nm thick.

Explain why the nanosheet layer would be better than aluminium as a coating for crisp packets.

Nanosheet layers can be made from amino acids.

An equation showing a reaction of an amino acid, C₂H₅NO₂, is

Calculate the mass of water formed when 105 g of this amino acid reacts.

(relative formula masses: C₂H₅NO₂ = 75, H₂O = 18)

Some crisps contain malic acid.

The structure of one molecule of malic acid is shown in Figure 16.

Malic acid has two types of functional group.

One type is the –COOH functional group.

Give the name of this functional group.

Name the other functional group.

Crisp packets are often made from poly(propene) coated with a thin layer of aluminium on the inside.

Poly(propene) is a polymer made from the monomer propene, CH₂CHCH₃.

What is the relative formula mass of propene?

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

Describe how monomer molecules combine to make polymers.

Crisps go stale when exposed to the atmosphere.

In an experiment some crisp packets were made from aluminium, some from poly(propene) and some from poly(propene) coated with aluminium. These packets were tested.

Figure 5 shows the results.

Low porosity is an advantage of using poly(propene) coated with aluminium as it prevents the crisps from becoming damp.

Explain, using Figure 5, one other advantage of using poly(propene) coated with aluminium.

The aluminium coating can be replaced by a very thin layer of material called a nanosheet.

The nanosheet is made from amino acids and is less than 100 nm thick.

Explain why the nanosheet layer would be better than aluminium as a coating for crisp packets.

Nanosheet layers can be made from amino acids.

An equation showing a reaction of an amino acid, C₂H₅NO₂, is

Calculate the mass of water formed when 105 g of this amino acid reacts.

(relative formula masses: C₂H₅NO₂ = 75, H₂O = 18)

Some crisps contain malic acid.

The structure of one molecule of malic acid is shown in Figure 6.

Malic acid has two types of functional group.

One type is the –COOH functional group.

Give the name of this functional group.

Name the other functional group.

Figure 1 shows a metal spoon.

This spoon is made of silver.

Give a reason why silver is a suitable material to use for making a spoon.

Some spoons are made of wood or plastic, not metal.

The raw material for wooden spoons is trees and the raw material for plastic spoons is crude oil.

Explain an advantage, other than cost, of using wood rather than plastic.

Some people wear spectacles so that they can see more clearly.

Which property of glass makes it suitable for use in spectacles?

Some spectacles have a coating made of nanoparticles on the glass.

Which statement describes nanoparticles?

One nanoparticle has a cube shape that is shown in Figure 2.

Calculate the surface area of this nanoparticle.

surface area = area of one face × number of faces

Figure 1 shows toothbrushes in a container.

The toothbrush handles are made of plastic (polymer).

Give a reason why plastic is a suitable material to make a toothbrush handle.

Some toothbrush handles are made of wood, not plastic.

Explain a disadvantage of using plastics.

The container is made of a ceramic material.

Which is a property of the ceramic that makes it suitable for the container?

In some countries, toothpastes contain nanoparticles of silver.

Which statement describes the size of a nanoparticle?

Toothpastes contain abrasives and other substances to make them effective.

Figure 2 is a pie chart of the percentage composition by volume of one toothpaste.

Calculate the volume of water in 150 cm³ of this toothpaste.

Figure 1 shows a mug made of clay ceramic.

Which property of clay ceramic makes it suitable for use as a mug?

Figure 2 shows the properties of some materials.

Figure 3 shows an electrical cable. The electrical cable is made of metal wire coated with another material. The metal wire inside the electrical cable conducts electricity.

Name a material from Figure 2 that would be suitable for coating the metal wire.

Which type of particle moves through the metal wire to allow it to conduct electricity?

There are some concerns that nanoparticles may cause harm if they enter the human body.

Suggest one way that nanoparticles can enter the human body.

Suggest one possible risk if nanoparticles enter the human body.

The surface area of a nanoparticle of gold is 150 nm². The volume of a nanoparticle of gold is 125 nm³.

Calculate the surface area to volume ratio of this nanoparticle of gold.

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

Figure 2 shows information about three different materials, a composite, a glass and a metal.

Explain which material in Figure 2 is the most suitable material to use in electrical circuits.

Nanoparticles are very small.

Some nanoparticles have a radius of 17 nm. The radius of a magnesium atom is 0.16 nm.

Approximately how many times larger is the radius of these nanoparticles than the radius of the magnesium atom?

A catalyst contains cube‑shaped nanoparticles. Figure 3 shows a diagram of a cube‑shaped nanoparticle.

The length of each side of the cube is 9 nm.

Calculate the surface area of the cube, in nm².

surface area =_........ ²

Nanoparticles have many uses. Some scientists are concerned about the possible risks of using nanoparticles.

Give one possible risk of using nanoparticles.

(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).

Figure 4 shows information about a ceramic and a metal.

The ceramic, rather than the metal, is a more suitable material for washbasins.

Give a reason for this, using a property from Figure 4.

Poly(propene) is an example of a polymer.

The structure of a poly(propene) molecule is shown in Figure 5.

This polymer is made from a monomer.

Draw the structure of the monomer molecule showing all covalent bonds.

A layer of poly(chloroethene) (PVC) is used to surround the copper in electrical cables.

Explain why poly(chloroethene) is a suitable material for this purpose.

Some polymers are polyesters.

What type of reaction takes place when polyesters are formed?

The repeating unit in a polyester molecule is shown in Figure 6.

This polymer is made from two different monomers.

Draw a molecule of each monomer showing all covalent bonds.

Give the name or formula of the small molecule formed when the monomer molecules react to form an ester link.