Identifying metal halides with silver ions

Question 1

What reagent is used to test for halide ions in solution?

Answer 1

Silver nitrate (AgNO3) solution

Question 2

What is the general observation when a halide reacts with silver ntirate?

Answer 2

A precipitate of the silver halide forms (except for fluoride)

Question 3

Why doesn’t silver fluoride AgF form a precipitate in the halide test?

Answer 3

This is because it is soluble in water

Question 4

Why is dilute nitric acid added before silver nitrate in the halide test?

Answer 4

To remove carbonate (CO3 2-) and hydroxide (OH-) impurities that could form unwanted precipitates

Question 5

What unwanted precipitates could form if impurities are not removed before adding silver nitrate?

Answer 5

Silver carbonate (Ag2CO3) or silver hydroxide (AgOH)

Question 6

What is the ionic equation for the reaction between a halide ion and silver ion?

Answer 6

Ag+ (aq) + X- (aq) ⇒ AgX

Question 7

What is observed when silver nitrate is added to a halide solution?

Answer 7

A precipitate of silver halide forms

Question 8

What colour precipitate is formed with chloride ions (Cl-)?

Answer 8

White precipitate of silver chloride (AgCl)

Question 9

What colour precipitate is formed with bromide ions (Br-)?

Answer 9

Cream precipitate of silver bromide (AgBr)

Question 10

What colour precipitate is formed with iodide ions (I-)?

Answer 10

Yellow precipitate of silver iodide (AgI)

Question 11

How can you distinguish between silver bromide and silver iodine?

Answer 11

Add concentrated ammonia solution which will make silver bromide dissolve, whereas silver iodide does not dissolve

Question 12

What happens to silver chloride when dilute ammonia is added?

Answer 12

It dissolves in dilute ammonia