Chrominfo: Identification test for borax

Learn the identification test for borax through a laboratory experiment or practical.

Aim:

To perform identification test for borax.

Reference: Indian Pharmacopoeia (IP)

Requirements:

Glasswares and miscellaneous:

Test tube, measuring cylinder, pipette, glass rod, volumetric flask, beaker, porcelain dish, dropper, rubber stopper, test tube stand, test tube holder, turmeric paper, balance, etc.

Chemicals:

Borax (Na₂[B₄O₅(OH)₄]•8H₂O), sodium hydroxide (NaOH), hydrochloric acid (HCl), sulphuric acid (H2SO4), ammonia solution, etc.

Theory of identification test for borax:

Identification tests are used to determine the drug's quality so that it can be used safely. Borax, commonly known as sodium tetraborate, sodium borate, or disodium tetraborate, is a transparent, colorless crystal.

It's commonly used as a household cleaner and a laundry detergent booster. It is a bacteriostatic and pharmaceutical aid. It is an odorless, alkaline chemical with a salty taste. Borax is soluble in boiling water, slightly soluble in water, and insoluble in alcohol.

Procedure of identification tests for borax:

Acidify 5% borax solution with HCl, then moisten a piece of turmeric paper with it, and dry. The paper turns pink or brownish-red in color. On the paper, put a dilute ammonia solution or a sodium hydroxide solution. The paper turns a blue or greenish-black color.
In a porcelain dish, ignite a mixture of borax, sulfuric acid, and alcohol by which a greenish-tinged flame is produced.