Chrominfo: Identification test for sodium chloride

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

Aim:

To perform identification test for sodium chloride.

Reference: Indian Pharmacopoeia (IP)

Requirements:

Glasswares and miscellaneous:

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

Chemicals:

Sodium chloride (), potassium carbonate (K2CO3), silver nitrate (AgNO3), potassium dichromate (K2Cr2O7), magnesium uranyl acetate (MGUO2), diphenylcarbazide (C13H14N4O), ammonia (NH3), sulphuric acid (H2SO4), sodium antimonite (NaSb(OH)6), acetic acid (CH3COOH), nitric acid (HNO3), etc.

Theory:

This identification of NaCl is usually based on the reactions of ions and cations present in the sample, by which we can determine the quality of the drug. Sodium chloride is also known as a salt, an ionic compound, with the chemical formula NaCl.

It comes in colorless cubic crystals or white crystalline powder, which is odorless and has a saline taste. It is used as an electrolyte replenishment and pharmaceutical aid. It is soluble in water, methanol, ammonia, and glycerin; and slightly soluble in ethanol.

Procedure:

To perform the following tests, prepare a sample solution by dissolving 01.00 g in 20.00 ml of distilled.

Identification tests for sodium ions:

Take 02 ml of prepared sample solution and 2 ml (15% w/v) of potassium carbonate solution, and heat it to boiling. No precipitate is formed, then add 04 mL of freshly antimonite solution and heat to a boil. Then cool in an ice bath and, if required, rub the inside wall of the test tube with a glass rod. A dense white precipitate of NaSb (OH) 6 is formed.
Using acetic acid, acidify 1 ml of the above solution, and add additional magnesium uranyl acetate solution. The yellow crystalline precipitate of sodium magnesium uranyl acetate is formed.

Identification tests for chloride ion:

Take 01 ml of dilute nitric acid and add it to 03 ml of prepared chloride solution. Then add 2-4 drops of silver nitrate solution. A white precipitate of AgNO3 is formed. When dilute ammonia is added, the precipitate dissolves to form a complex.
Add 0.2 g potassium dichromate and 01 ml H2SO4 to a small amount of sodium chloride in a test tube. Over the mouth of the test tube, place a filter-paper strip moistened with 0.1 ml diphenylcarbazide solution. The paper turns violet-red.