Group 7/The Halogens

Question 1

What is the state and colour of fluorine at room temperature and what is a use for it?

Answer 1

Pale yellow gas, used in dental products

Question 2

What is the state and colour of chlorine at room temperature and what is a use for it?

Answer 2

Pale green gas, used to disinfect water in swimming pools etc

Question 3

What is the state and colour of bromine at room temperature and what is a use for it?

Answer 3

Red/brown liquid, used in agriculture as a fire retardant

Question 4

What is the state and colour of iodine at room temperature and what is a use for it?

Answer 4

Grey, slightly metallic solid, used in printing inks and dyes

Question 5

What is a diatomic molecule?

Answer 5

Diatomic molecules are two elements of the exact same type chemically bonded. You will never find one of these elements alone as they are too unstable

Question 6

What are the observations when chlorine reacts with iron wool?

Answer 6

• Brown fumes (iron chloride)
• Chlorine (pale green gas) disappears

Question 7

What are the observations when bromine reacts with iron wool?

Answer 7

• Bromine (brown/red liquid) goes to brown gas

Question 8

What are the observations when iodine reacts with iron wool?

Answer 8

• Colour changes from silver to purple
• Dull glow (not very vigorous)
• Solid iodine sublimes to a gas
• Slow reaction

Question 9

What is the trend in reactivity in the halogens?

Answer 9

As you go down, the reactions get less vigorous