Exam Questions Feedback

Question 1

What 3 properties would be suitable for use as an insulator inside electrical transformers?

Answer 1

• non-flammable so it does not burn
• does not conduct electricity so can insulate
• extremely un-reactive so it does not react to materials inside the transformer

Question 2

What is an ore?

Answer 2

rock that consist of metals which can be extracted for economic gain

Question 3

Why do ions move to the positive electrode?

Answer 3

negatively charged ions are attracted to the anode

Question 4

Why do alkaline batteries eventually stop working?

Answer 4

a reactant is used up

Question 5

What gas is produced at the negative electrode?

Answer 5

hydrogen

Question 6

Why can alkaline batteries not be charged?

Answer 6

the reaction is reversible

Question 7

Advantages and Disadvantages of Hydrogen Fuel Cells

Answer 7

Fuels cells do not need electronically recharging
Hydrogen is very flammable and explosive
No pollutants are produced, the only waste product is water
The hydrogen produced for the fuel cell can be produced from non-renewable resources
They can be made into different sizes for different uses
Hydrogen is very difficult to store, due to being a gas at room temperature and explosive

Question 8

How could students find the total mass of copper produced?

Answer 8

• filter the mixture
• wash and dry copper
• weigh copper collected
• add to the increase the mass of the electrode

Question 9

Suggest how the oxygen removes most of the carbon from the molten iron?

Answer 9

oxygen reacts with the carbon from the molten iron and produced carbon dioxide

Question 10

Give one use of a fullerene?

Answer 10

deliver drugs inside the body

Question 11

Explain why the reactivity of elements changes going down Group 1?

Answer 11

outer shell of electrons gets further away from the nucleus so there is less attraction between the electrons and nucleus so the electron is more easily lost

Question 12

Suggest 2 improvements to the titration experiment?

Answer 12

• place a white tile under the conical flask to see the colour change
• add acid solution drop wise to the endpoint

Question 13

Why is it important to warm the acid in crystallisation?

Answer 13

increase rate of reaction

Question 14

Why is it important to filter the mixture?

Answer 14

remove excess of unreacted copper oxide

Question 15

Explain the trends in the boiling points of halogens?

Answer 15

as you down the column, the boiling pint increases as the molecular mass increases so the intermolecular forces increase which requires a lot of energy to overcome.

Question 16

Explain the trends in the reactivity of halogens?

Answer 16

as you go down the column, the user shell of electrons gets further away from the nucleus, less attraction between the nucleus and outer electrons so less likely to gain electrons