Testing and Identifying Halide Ions

Aim:To identify the conclusive chemical tests for Halide ions.

Chloride Cl-1;Bromide Br-1;Iodide I-1

•Add about 2ml of aqueous chloride to a test tube

•Add an equal volume of dilute HNO3

•Add a few drops of silver (I) nitrate to the tube

•Pour half of the contents of the tube into a clean test tube

•To the 1st tube add dilute ammonia until no further change

•To the second tube add CONC AMMONIA until there is no further change – Do this in a fume cupborad

•Repeat with aqueous solutions of bromide and iodide

Results Table

Halide Ion HNO3 then AgNO3

Action of dilute NH3 on product

Action of conc NH3 on product

Cl-1

Br-1

I-1

Results Table

Halide Ion HNO3 then AgNO3

Action of dilute NH3 on product

Action of conc NH3 on product

Cl-1 White ppt White ppt dissolves

Br-1

I-1

Results Table

Halide Ion HNO3 then AgNO3

Action of dilute NH3 on product

Action of conc NH3 on product

Cl-1 White ppt White ppt dissolves White ppt dissolves

Br-1

I-1

Results Table

Halide Ion HNO3 then AgNO3

Action of dilute NH3 on product

Action of conc NH3 on product

Cl-1 White ppt White ppt dissolves

Br-1 Cream ppt

I-1

Results Table

Halide Ion HNO3 then AgNO3

Action of dilute NH3 on product

Action of conc NH3 on product

Cl-1 White ppt White ppt dissolves

Br-1 Cream ppt No reaction Cream ppt dissolves

I-1

Results Table

Halide Ion HNO3 then AgNO3

Action of dilute NH3 on product

Action of conc NH3 on product

Cl-1 White ppt White ppt dissolves

Br-1 Cream ppt Insoluble Cream ppt dissolves

I-1 Yellow ppt Insoluble insoluble

Identifying Unknown Halide Solutions

• Using the tests for chloride, bromide and iodide ions test the solutions labelled A, B, C and D to identify the ions present.

Halide

Soln

PPt colour?

Dil Ammonia?

Conc ammonia?

Halide?

A

B

C

D

Ionic Equations for the reaction

• Sodium chloride + Silver nitrate

• NaCl + AgNO3

• Write the ionic equation for the reaction for Sodium Bromide and Silver iodide as above.