Test For Halide Ions

Question 1

Reaction with silver ions equation

Answer 1

Ag+ (aq) + X- (aq) ➡️ AgX (s)

Replace X with Cl, Br or I

Question 2

Why is nitric acid added to this reaction with silver ions

Answer 2

to ensure that any carbonate or hydroxide ions, often found as impurities with halide ions, are removed as CO2 or water and so do not interfere with the precipitate.

Question 3

Chloride ion (halide) reaction with
silver nitrate
dilute aqueous ammonia
conc. aqueous ammonia

Answer 3

• white ppt forms
• white ppt dissolves to form clear colourless sol.
• no reaction

Question 4

Bromide ion (halide) reaction with
silver nitrate
dilute aqueous ammonia
conc. aqueous ammonia

Answer 4

• cream ppt forms
• no visible change
• cream ppt dissolves to form colourless sol.

Question 5

Iodide ion (halide) reaction with
silver nitrate
dilute aqueous ammonia
conc. aqueous ammonia

Answer 5

• yellow ppt forms
• no visible change
• no visible change

Question 6

Full chemistry test for Cl- (aq)

Answer 6

add dilute AgNO3 (aq), with a little nitric acid, to the solution.

A white precipitate will form which is soluble in dilute ammonia.

Question 7

Full chemistry test for Br- (aq)

Answer 7

add dilute AgNO3 (aq), with a little nitric acid, to the solution.

A cream precipitate will form which is insoluble in dilute ammonia but soluble in concentrated ammonia.

Question 8

Full chemistry test for l- (aq)

Answer 8

add dilute AgNO3 (aq), with a little nitric acid, to the solution.

A yellow precipitate will form which is insoluble in dilute ammonia and also insoluble in concentrated ammonia.