Ammonium Chloride

Ammonium chloride is a white, odorless, crystalline inorganic compound with the chemical formula

N

H

4

C

l

NH

4

Cl. It is highly soluble in water, producing a mildly acidic solution due to the ammonium ion's hydrolysis. The compound is known for its sublimation property—on heating, it transitions directly from solid to gas, releasing ammonia and hydrogen chloride gases.

Key Properties

Chemical Formula:

N

H

4

C

l

NH

4

Cl​

Molar Mass: 53.49 g/mol​

Appearance: White, granular or crystalline powder; odorless​

Density: 1.52–1.53 g/cm³​

Melting/Sublimation Point: ~338–340 °C (sublimes without melting)​

Solubility: Highly soluble in water, forms a slightly acidic solution (pH 4.6–6.0 for 5% in water)​

Hygroscopic: Absorbs moisture from the air​

Chemical Properties and Reactions

Decomposes to release ammonia and hydrogen chloride on heating:

N

H

4

C

l

→

N

H

3

+

H

C

l

NH

4

Cl→NH

3

+HCl.​

Reacts with strong bases (e.g., sodium hydroxide) to produce ammonia gas.​

Reacts with sodium carbonate to yield sodium chloride, carbon dioxide, water, and ammonia.​

Applications

Fertilizer: Source of nitrogen for crops.​

Metallurgy: Used in galvanizing, tinning, and soldering of metals to remove oxide coatings.​

Medicine: Expectorant in cough medicine.​

Batteries: Common electrolyte in dry cell batteries.​

Laboratory: Used in buffer solutions and analytical chemistry.​

Food Additive (E510): Used as a yeast nutrient in breadmaking and as a food additive in licorice.​

Safety

Relatively low toxicity but can cause irritation if inhaled or ingested in large amounts.

Should be handled with basic chemical safety measures.