Chem Paper 2 Exam Qs

2024: (4)

2024

to recycle remaining nitrogen and hydrogen

2024: Ammonia and nitric acid react to produce the salt, ammonium nitrate. Ammonium ions and nitrate ions both contain nitrogen.

Suggest one use of ammonium nitrate. (1)

fertilisers

2024: (2)

reversible, combustion

2024: (6)

2024: Why is the Rf value of a dye not affected by how far the solvent front is allowed to travel? (1)

the ratio/proportion of spot distance to solvent distance is fixed/constant

2024: Advantages of instrumental methods (2)

• more sensitive

• more accurate

• faster

2024: Explain how oxides of nitrogen are produced when burning fuels (2)

• nitrogen and oxygen (from air) react

• at high temperatures

2024: Explain one positive impact on the environment of burning hydrogen rather than natural gas as a fuel (2)

Use table 2

• less climate change/global warming

• because no carbon dioxide produced

Effects of oxides of nitrogen

• acid rain

• respiratory problems

2024:

2024 (3)

Are metals finite or renewable resources?

finite

2024: Explain why aluminium alloy bicycle frames do not need protection from corrosion. (2)

• aluminium has an oxide coating

• so contact between aluminium and water/air/oxygen is prevented

2024: Suggest how bicycle chains made from an alloy of iron can be protected from rusting without using paint (1)

any one from:

• coating with grease

• coating with oil

• galvanise

2024: To produce sulfur trioxide, a reversible reaction is used

To favour the products, a higher pressure should be used

In industry, the reaction is done at 450 °C and atmospheric pressure.

Under these conditions the yield of sulfur trioxide is 86%.

Suggest two reasons why a higher pressure is not used. (2)

2024 (1)

2024: Describe what will be seen when an alkene is shaken with bromine water (2)

• orange bromine water

• turns colourless

2024

2024: Explain why some polymers do not melt when heated. (2)

(thermosetting polymers)

• cross-links between polymer chains

• so too much energy needed to overcome the cross-links

2024

• some hydrogen/gas escapes

• before the stopper is put in