4b: Testing for halide ions in solution

Question 1

What is the ionic equation for silver nitrate reacting with a halide ion

Answer 1

Ag+(aq) + X-(aq) = AgX(s)

Question 2

What is the equation for when a silver halide dissolves in ammonia

Answer 2

AgX(s) +2NH3(aq) = (Ag(NH3)2)+(aq) + X-(aq)

Question 3

How can you test for a halide ion

Answer 3

add sodium hydroxide [a strong base] that can break apart the ions

Add dilute nitric acid

followed by silver nitrate solution

A white, cream, yellow precipitate can confirm the presence of a halide ion

Question 4

What color precipitate does chloride produce

Answer 4

A white precipitate that dissolves in dilute and concentrated ammonia

Question 5

What color precipitate does bromide produce

Answer 5

A cream precipitate that remains in dilute ammonia but dissolves and concentrated ammonia

Question 6

What color precipitate does iodide form

Answer 6

A pale yellow/yellow precipitate that remains in dilute and concentrated ammonia

Question 7

What is the formation/ Compound of the precipitate

Answer 7

AgCl
AgBr
AgI

Question 8

Why does the fluoride ion not produce a precipitate

Answer 8

because silver fluoride AgF is soluble therefore no precipitate is formed