Ammonium chloride is an inorganic compound that occurs as a white crystalline powder. It is highly soluble in water and solutions are mildly acidic. Ammonium chloride is prepared commercially by reacting ammonia with hydrogen chloride gas or hydrochloric acid. It has several applications, including use as an expectorant in cough medicines due to its irritating effect on the bronchial mucosa. Ammonium chloride is also used to acidify the urine and as a systemic acidifying agent to treat metabolic alkalosis. It is available in formulations like cough syrups and injections.

1. Inorganic Salts
Ammonium Chloride USP
Mahpara Gondal
Rashid Latif College of Pharmacy

2. Objectives
Students will learn about ……
• Introduction of Ammonium chloride
• Physical properties
• Chemical properties
• Preparation
• Applications
• Dosage form

3. Ammonium Chloride
• Ammonium chloride is an inorganic compound
with the formula NH4Cl and a white crystalline
salt that is highly soluble in water. Solutions of
ammonium chloride are mildly acidic.
• OCCURANCE
• Sal ammoniac is a name of the natural,
mineralogical form of ammonium chloride. The
mineral is commonly formed on burning coal
dumps from condensation of coal-derived gases.
It is also found around some types of volcanic
vents. It is mainly used as fertilizer and a
flavouring agent in some types of liquorice.

4. Ammonium Chloride USP
Formula: NH4Cl
Mol Wt : 53.50g/mol
PHYSICAL PROPERTIES
It occurs as white, fine or coarse crystalline powder.
Odor: odorless
Taste: cooling salty taste
Density: 1.53g/cm3
Solubility: Very soluble in water
Melting Point:338°C
PH: Its aqueous solution is weakly acidic, having PH 4.6

6. Chemical Properties
• 1. Ammonium chloride appears to volatilize upon heating but actually not
decomposes in the process. Its decomposition is reversible and components
reunite again when cooled. On heating convert into ammonia and hydrogen
chloride gas.
NH4Cl → NH3 + HCl
• 2. Ammonium chloride reacts with a strong base, like sodium hydroxide, to
release ammonia gas:
NH4Cl + NaOH → NH3 + NaCl + H2O

7. Similarly, ammonium chloride also reacts with alkali metal carbonates at elevated
temperatures, giving ammonia and alkali metal chloride:
2 NH4Cl + Na2CO3 → 2 NaCl + CO2 + H2O + 2 NH3
• 3. Freshly prepared solution of NH4Cl is neutral in reaction but due to hydrolysis
the solution quickly becomes slightly acidic in reaction on standing A molar
solution of ammonium chloride in water has a pH in the range 4.6 to 6.0.
+ - + 0
NH4 + Cl + 2H2O NH4OH + H3O + Cl

8. Preparation
• 1. Ammonium chloride is prepared commercially by combining ammonia
(NH3) with either hydrogen chloride (gas) or hydrochloric acid (water
solution)
NH3 + HCl → NH4Cl
Ammonium chloride occurs naturally in volcanic regions, forming on volcanic
rocks near fume-releasing vents (fumaroles). The crystals deposit directly from
the gaseous state and tend to be short-lived, as they dissolve easily in water.

9. • Demonstration of a synthesis of ammonium chloride. Concentrated
ammonia and hydrochloric acid solutions are added to two gas-washing
bottles, respectively. Using rubber pumps, air (acting as gas-carrier) is
injected in the gas-washing tubes causing the streams of ammonia and
hydrogen chloride in air to collide and react giving the solid product,
ammonium chloride.

10. 2. It is a product of the Solvay process used to produce sodium carbonate
CO2 + 2 NH3 + 2 NaCl + H2O → 2 NH4Cl + Na2CO3
In addition to being the principal method for the manufacture of ammonium
chloride, that method is used to minimize ammonia release in some industrial
operations.
3. It can also be produced by reaction of NaCl with NH4HCO3.
NaCl + NH4HCO3 NH4Cl + NaHCO3

11. Applications
• Ammonium chloride is used as an expectorant in cough medicine. Its
expectorant action is caused by irritative action on the bronchial mucosa,
which causes the production of excess respiratory tract fluid, which
presumably is easier to cough up.
• Side effect : Ammonium salts are an irritant to the gastric mucosa and may
induce nausea and vomiting.
• Ammonium chloride is used as a systemic acidifying agent in treatment of
severe metabolic alkalosis, It also shows diuretic action ,and in high doses
produces acidic urine or to maintain the urine at an acid pH in the treatment
of some urinary-tract disorders.

12. Contrindicated
• Patients with renal and hepatic impairment
because of risk of ammonia toxicity.

13. Dosage form
• Ammonium chloride cough syrup
• Ammonium chloride injection
• ammonium chloride/chlorpheniramine/codeine/phenylephrine
systemic
• Brand names: Rolatuss
Drug class(es): upper respiratory combinations