Testing for ions

Question 1

What is the test for halide ions?

Answer 1

Add silver nitrate to the solution and then first dilute then concentrated ammonia.

Question 2

What is the result for chloride ions?

Answer 2

A white precipitate forms which dissolves in both dilute and concentrated ammonia

Question 3

What is the result for bromide ions?

Answer 3

A cream precipitate forms which doesn’t dissolve in dilute ammonia but does dissolve in concentrated ammonia

Question 4

What is the result for iodide ions?

Answer 4

A yellow precipitate which doesn’t dissolve in either dilute or concentrated ammonia

Question 5

Why is the halide test useful as a chemical test?

Answer 5

It has easily observable results, the results are distinguishable between ions, it’s an instant reaction and only requires only basic equipment

Question 6

What is the test for sulfate ions?

Answer 6

Add barium chloride solution to the solution

Question 7

What is the result for sulfate ions?

Answer 7

If a white precipitate forms, sulfate ions are present

Question 8

What is the test for carbonate ions?

Answer 8

Add dilute nitric acid and if effervescence occurs, pass the gas through lime water

Question 9

What is the result for carbonate ions?

Answer 9

If the gas is bubbled through results in a white precipitate in the lime water, carbonate ions are present

Question 10

What is the test for ammonium ions?

Answer 10

Add sodium hydroxide to the solution and heat the test tube in a boiling water bath 2 minutes. Then hold damp red litmus paper above the mouth of the test tube

Question 11

What is the result for ammonium ions?

Answer 11

If the litmus paper turns blue and there is the smell of ammonia, ammonium ions are present