Question

Dry and wet test for anion

Answer 1

There are many test which is done in the laboratory for the Identification of the Cation and Anion in the Laboratory.

Since, you have not mentioned the one anion which need to be tested, therefore let me give the simple applications which are used for detection of salts in the laboratory.

Detection of Cation and Anion is the Part of the Chemistry Practical of Class 11th and 12th, and it is one of the Interesting practical.

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1. Dry and wet test for anion ⇒ The dry test of anion is a basic test performed to detect the presence of element in compound by introducing the sample to the flame for noting the color produced, since some common and the certain element can be detected by means of their characteristic flame color.  

The wet test of an anion is the test which is based on the principle of treating solution with succession of reagents so that each reagent can separate a group of reagent.

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Dry and wet test is also performed for the Cation, thus it is given below, you can see that also for more information.

2. Dry and wet test of Cation ⇒   Dry tests are those tests which are performed with the solid salt (or a mixture of salts), while wet tests are those tests which are preformed by dissolving the salt. (or mixture of salts) in water, acid or any other solvent.

Generally in dry and wet test for colored salts,  we uses a compound named Sodium Borate. Sodium Borate(or Borax) is one of the compound of the Boron which is the mandatory part of every chemistry laboratory.

Chemical formula for Sodium Borate is Na₂[B₄O₅(OH)₅]·8H₂O.

For Uncolored salts, other solvents like Mohr's salt or Kessler's Reagfent is used.

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Hope it helps.

Answer 2

DRY TEST:

A preliminary test performed for testing the presence of an element in a compound is a dry test. Here the sample is introduced to the flame to check the colour produced. Based on the colour, the properties of the element can be understood.

Examples:

• Sodium carbonate bead tests
• Flame tests
• Borax bead tests etc.

WET TEST:

Wet Testing for anions involves treating the solutions with reagents to give precipitates. The by-products are further dissolved to give anions. This process is repeated until the anions are formed.  

Example:

• Brown ring test with Silver Nitrate and Barium chloride.
• Salt or mixture treated with dilute Sulphuric acid, confirmatory tests are performed for anions.
• Bromide test etc.