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.
Observation table:
Sr. |
Identification
test |
Observation |
Inference |
1 |
5% of sample
solution+ HCl → Using this solution, moisten a piece
of turmeric paper. |
Paper turns pink or brownish red |
Borax: Present/Absent |
2 |
In a porcelain dish, ignite a mixture |
Greenish
flame |
Borax: Present/Absent |
Result:
The given sample is identified as borax.
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