Bulk & Surface Properties Practice Questions

Question 1

4 marks

Table 1 gives the diameters of four particles found in a sample of air collected near a busy road.

Particle	Diameter
A	$50$ nm
B	$900$ nm
C	$1.5 \times 10^{-6}$ m
D	$5 \times 10^{-6}$ m

(a)

Classify each particle in Table 1 as a nanoparticle, a fine particle (PM2.5) or a coarse particle (PM10).

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(b)

Give the diameter of particle A in metres.

Give your answer in standard form.

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(c)

The diameter of a typical atom is about $0.1$ nm.

Calculate how many times larger the diameter of particle A is than the diameter of an atom.

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Question 2

3 marks

Nanoscience is an important area of research.

(a)

Which row gives the range of sizes of nanoparticles?

Tick one box.

	Size range
A	$1$ nm to $100$ nm
B	$100$ nm to $2500$ nm
C	$1$ nm to $2500$ nm
D	$2500$ nm to $10\,000$ nm

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(b)

Nanoparticles are used in sun creams.

Give two other uses of nanoparticles.

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Question 0

5 marks

Zinc oxide is used in sun creams and in ointments for skin.

A nanoparticle of zinc oxide can be modelled as a cube with sides of length $2$ nm, as shown in Figure 1.

Figure 1

(a)

Calculate the surface area to volume ratio of the cube in Figure 1.

Give your answer as the simplest whole number ratio.

Surface area : volume = ................ : ................

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(b)

A fine particle of zinc oxide can be modelled as a cube with sides of length $200$ nm.

Describe how the surface area to volume ratio of this cube differs from that of the cube in Figure 1.

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(c)

Suggest why a smaller mass of zinc oxide is needed in a sun cream when nanoparticles are used instead of fine particles.

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Question 0

4 marks

Table 2 gives information about two sun creams.

	Sun cream A (nanoparticles of titanium dioxide)	Sun cream B (fine particles of zinc oxide)
Mean particle diameter	$40$ nm	$400$ nm
Appearance on the skin	transparent	white
Mass of metal oxide in $100$ g of cream	$3$ g	$12$ g
Percentage of UV radiation blocked	$97\%$	$94\%$
Metal oxide particles detected in blood after use	small amounts detected	none detected

Use the information in Table 2 to evaluate the use of sun cream A instead of sun cream B.

Give a conclusion.

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Question 0

4 marks

Some sports socks contain silver nanoparticles. The silver kills the bacteria that cause unpleasant smells.

(a)

Explain why silver nanoparticles kill bacteria more effectively than the same mass of fine silver particles.

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(b)

Suggest two possible risks of using silver nanoparticles in socks.

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Question 0

6 marks

Platinum is used as a catalyst. In a catalytic converter the platinum is spread out as nanoparticles.

A cube of platinum has sides of length $1$ mm.

The cube is divided up into nanoparticles which are cubes with sides of length $10$ nm.

$1$ mm $= 1 \times 10^{6}$ nm

(a)

Calculate the total surface area, in m $^2$ , of all of the nanoparticles formed.

Give your answer in standard form.

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(b)

The surface area of the original $1$ mm cube of platinum was $6 \times 10^{-6}$ m $^2$ .

Explain why using platinum nanoparticles reduces the mass of platinum needed in a catalytic converter.

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Atomic Structure & the Periodic Table

Bonds, Structure & Properties of Matter

Quantitative Chemistry

Chemical Changes

Energy Changes

Chemical Change: Rate & Extent

Organic Chemistry

Chemical Analysis

Chemistry of the Atmosphere

Using Resources

Question 1

Question 2

Question 0

Question 0

Question 0

Question 0