Pure aluminium is soft. Aircraft bodies are made from aluminium alloys.
.1
Explain why pure aluminium is soft.
[2 marks].2
Explain why aluminium alloys are harder than pure aluminium.
[2 marks]Edexcel GCSE Chemistry November 2020 Paper 2F
5 questions on this paper's topics
20:001 of 5
A student adds marble chips to hydrochloric acid and collects the carbon dioxide in a gas syringe.
| Time in s | 0 | 10 | 20 | 30 | 40 | 50 | 60 |
|---|---|---|---|---|---|---|---|
| Volume in cm³ | 0 | 22 | 38 | 50 | 56 | 60 | 60 |
.1
Calculate the mean rate of reaction in the first 30 seconds.
[2 marks].2
Give the earliest time in the table by which the reaction had stopped.
[1 mark].3
Describe how the rate changes during the reaction.
[1 mark]A teacher adds a small piece of lithium to a trough of water containing universal indicator.
.1
Give two observations the students would see.
[2 marks].2
Complete the word equation: lithium + water → lithium hydroxide + ______
[1 mark].3
The teacher repeats the demonstration with potassium. Predict how the reaction compares.
[1 mark]Magnesium reacts with oxygen to form magnesium oxide, an ionic compound.
The electron structure of magnesium is 2,8,2 and of oxygen is 2,6.
.1
Describe what happens to the electrons when magnesium reacts with oxygen.
[2 marks].2
What are the charges on the ions in magnesium oxide?
[1 mark].3
Name the type of force that holds the ions together.
[1 mark]Crude oil is a mixture of hydrocarbons.
.1
Define the term hydrocarbon.
[1 mark].2
Butane has 4 carbon atoms. Write the formula of butane.
[1 mark].3
Which fraction is used as fuel for aircraft?
[1 mark]