1C Jan 2013

Question 1

What colour is chlorine gas?

Answer 1

Green

Question 2

What is bromine at room temperature?

Answer 2

Liquid

Question 3

Iron + sulphuric acid

Answer 3

iron sulphate + hydrogen

Question 4

Hydrous copper sulphate?

Answer 4

CuSO4.5H20

Question 5

Why is helium more suitable for filling balloons than hydrogen?

Answer 5

Non-flammable

Question 6

Show the process that occurs when hydrogen is liquefied.

Answer 6

H2(g) -> H2(l)

Question 7

During the extraction of aluminium what is the half equation at the anode?

Answer 7

2O2– → O2 + 4e–

Question 8

During the extraction of aluminium what effect does this reaction have on the positive electrodes?

Answer 8

Electrodes get smaller.

Question 9

In the blast furnace name the raw material that reacts with oxygen and state why the reaction is important.

Answer 9

Coke - produces heat.

Question 10

Name two uses of CO2 and why CO2 is good for these?

Answer 10

Carbonating drinks - soluble in water. Fire extinguishers - denser than air.

Question 11

What does the negative H indicate about the reaction?

Answer 11

Exothermic.

Question 12

Explain how the atoms are held together in a hydrogen bromide molecule.

Answer 12

Shared electrons attracted to both nuclei.

Question 13

Explain why sodium bromide has a higher melting point than hydrogen bromide.

Answer 13

Ionic bonding + and - ions. Ionic bonding is stronger so more energy is required to break bonds, therefore higher melting point.