Nanoparticles

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.

A student carries out a flame test on a salt. The student observes a yellow flame.

Which ion is in the salt?

A molecule of a yellow substance is shown in Figure 1.

What is the formula of this molecule?

A bottle of this substance is labelled with the hazard symbol in Figure 2.

State the danger associated with the contents of this bottle.

Yellow bananas emit ethene gas, C₂H₄.

Draw one molecule of ethene, showing all covalent bonds.

Gold has a yellow colour.

A gold nanosphere has a surface area of 305 nm². The surface area to volume ratio is 1: 4.60.

Calculate the volume, in nm³, of the gold nanosphere.

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

Concrete is a composite material made of cement, sand and stone.

Different types of concrete are produced by changing the ratio of cement, sand and stone.

Figure 1 shows some information about three different types of concrete,

State how the amount of stone added to the mixture affects the compressive strength of concrete.

What mass of stone is in a sample of concrete B containing 5000 kg of sand?

Sand contains silicon dioxide.

Figure 2 shows part of the structure of silicon dioxide.

State the type of structure and bonding in silicon dioxide.

Which statement about nanoparticles is correct?

Some sunscreens contain nanoparticles of titanium dioxide.

Explain why nanoparticles of titanium dioxide are used in some sunscreens.

Atoms, molecules, nanoparticles and protons are types of particle.

List these four types of particle in order of size from smallest to largest.

Nanoparticles have a large surface area to volume ratio.

Figure 7 shows a cube-shaped nanoparticle with sides of 90 nm.

Figure 7

What is 90 nm in metres?

Calculate the simplest surface area to volume ratio for the nanoparticle in Figure 7.

Show your working.

surface area to volume ratio = 1:_........

Figure 8 shows the structure of a molecule of tetrafluoroethene.

Tetrafluoroethene can form the polymer poly(tetrafluoroethene).

Draw a diagram to show the structure of the repeating unit of this polymer.

Poly(tetrafluoroethene) is also known as Teflon^TM.

State one use of poly(tetrafluoroethene) and explain how one of its properties makes it suitable for that use.

use

explanation

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.

Titanium dioxide nanoparticles are used in some sunscreens.

State one property of titanium dioxide nanoparticles that make them suitable for use in sunscreens.

Suggest one possible risk associated with using nanoparticles.

Figure 1 shows the surface area to volume ratio for different diameters of spherical nanoparticles.

State the trend shown by the data in Figure 1.

What is the surface area: volume ratio for a spherical nanoparticle with a diameter of 80 nm?

A different nanoparticle is cube shaped, as shown in Figure 2.

The length of one side of this cube is 60 nm.

Show that the surface area: volume ratio for this cube is 1: 10.

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 1 shows a list of particles.

ethene molecule nanoparticle sodium atom starch molecule

Figure 1

In the spaces below, write the names of these particles in order of increasing particle size.

Explain a possible risk associated with nanoparticulate materials.

Explain the advantage of using catalysts made of nanoparticles rather than larger particles.

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 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.

Titanium(IV) oxide is an ionic solid. Many ionic solids are soluble in water.

Titanium(IV) oxide is not soluble in water. Its other physical properties are typical of ionic solids.

Predict one other physical property of titanium(IV) oxide that would be typical of ionic solids.

The formula of titanium(IV) oxide is TiO₂.

Deduce the charge of the titanium ion in titanium(IV) oxide.

Nanoparticles are very small particles that have unusual properties.

Particles less than 100 nanometres in size are classified as nanoparticles.

100 nanometres is

Nanoparticles of titanium(IV) oxide are used in some sunscreens.

Describe a reason why nanoparticles of titanium(IV) oxide are used in some sunscreens.

Some people are concerned that there is a risk when sunscreens containing nanoparticles are used.

Explain a possible risk associated with using nanoparticles in sunscreens.

(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.