C2 Displacement Reactions Of Group 7

Question 1

Which elements take part in displacement reactions?

Answer 1

Group 7 halogens

Question 2

What happens in a displacement reaction?

Answer 2

A more reactive element pushes out (displaces) a less reactive element from a compound.

Question 3

Chlorine is more reactive than bromine (it’s higher up group 7). What will happen if you ass chlorine water to potassium bromide solution?

Answer 3

The chlorine will displace the bromine from the salt solution.

The chlorine is reduced to chlorine ions, so the salt solution becomes potassium chloride.

Question 4

Why does the solution turn orange when chlorine water is added to potassium bromide?

Answer 4

The bromide ions are oxidised to bromine, which turns the solution orange.

Question 5

See p 25 for equation for reaction

Answer 5

Halogen displacement reactions all follow this pattern

Question 6

See p25 for practical

Answer 6

.

Question 7

A student added a few drops of a halogen solution to some potassium iodide solution. The solution turned brown. She added a few drops of the same halogen solution to some potassium bromide solution. No reaction occurred. Name the halogen solution that the student used. (1 mark)

Answer 7

Bromine water