Question

How do you test for chloride?

Answer 1

Hint : Chloride ions are detected in a solution when they form a precipitate of insoluble chloride salt. Precipitation indicates that chloride ions are present in the solution. This is because a precipitate involves the combination of anions and cations.

Complete Step By Step Answer:
To find out the presence of chloride ions, precipitation reactions can be performed. The chloride ion becomes a part of the precipitate formed.
To test for chloride in a solution, firstly take the desired acidic aqueous solution in a beaker. Now add an equal volume of dilute nitric acid to this solution. Dilute nitric acid removes any interfering ions from the solution. No visible changes can be seen after the addition of dilute nitric acid. To this mixture, add a few drops of Silver nitrate. Soon you will observe a white precipitate which is silver chloride (AgCl) formed in the solution.
The reaction between dilute nitric acid and silver nitrate eventually leads to the formation of silver chloride. This silver chloride reacts with the given aqueous solution to form an insoluble or soluble salt depending on the salt it forms.
Now let's see the test for chloride ions in water.
The same process needs to be carried out to find the chloride ions in water. Take a test tube filled with deionized or distilled water. To this add, 5% dilute nitric acid. Using a dropper add a few drops of silver nitrate. If a cloudy white precipitate is formed, it indicates the presence of Chloride ions in water.

Note :
Only the formation of a precipitate will confirm the presence of chloride ions in the solution. So the solution should contain chloride ions to form a precipitate. The chloride ion is the anion, so the chloride test can be referred to as the ion test.