[Chemistry Class Notes] on Ammonium Hydroxide Pdf for Exam

In this article, we will discuss Ammonium hydroxide, its formula and structure use and properties. Do not forget to refer to the frequently asked questions at the end for clearing your doubts if you incur any while going through the topic.

Ammonia Hydroxide is a colourless liquid that comes under a class of substance known as costex. When Ammonia dissolves in water it results in the formation of ammonia hydroxide.

Ammonium hydroxide is a solution where ammonia is mixed in water. It is denoted by the symbols NH3(aq). The ammonium hydroxide is an alkali with a composition of [NH₄⁺]OH^– ions; it is not possible to isolate samples of NH₄OH.

 

Except in highly dilute solutions, the ions NH₄⁺ and OH^– do not account for a significant fraction of the total volume of ammonia.

 

The chemical is also known by many other names like:

• Ammonia water

• Ammoniacal liquor

• Ammonia liquor

• Aqua ammonia

• Aqueous ammonia

• Dilute ammonia

It is also known simply as Ammonia.

Chemical Formula for Ammonium Hydroxide: NH4OH or H5NO

 

IUPAC Name: Ammonium hydroxide

 

Synonyms: 

• Ammonium hydroxide

• Ammonia, aqueous solution

• Ammonium hydroxide solution

• Ammonia water

• Ammonia, monohydrate

Appearance: It appears as a colorless liquid

 

Structure

The compound structure is formed by one hydroxide anion (OH–) and one ammonium cation NH4+ which share an ionic bond. In the common representation used for organic molecules, its chemical structure can be written as below.

 

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Preparation of Ammonium Hydroxide

NH3 + H2O → NH4OH

 

The Ammonium hydroxide is prepared by saturating water with gaseous ammonia.

 

Properties

Physical Properties of Ammonium Hydroxide:

• Solubility – Miscible in water

• Specific gravity – It is typically 0.9 and actually depends on the strength of the solution.

• Melting Point – -57.5°C (25%).

• Boiling point – 38°C and 100°C based on the concentration

• Auto- Ignition temperature – 651°C.

• Molar Mass – molecular weight is 35.05 g/mol.

• Density – 0.91 g/cm³ (25%)

• Vapour pressure – Its v.p is 115 mm at 20°C

Chemical Properties:

Basicity of ammonia in water

 

Ammonium hydroxide is a weak basic compound that does not dissociate completely in water leaving the next equilibrium with ammonium ion and hydroxide ion

 

NH4OH + H2O ⇌ NH4+ + OH−

 

The equilibrium is used to control the pH in solutions because the ion OH^– raises a solution’s pOH or basicity level.

 

Saturated Solutions

Ammonia’s solubility is decreased in solvent liquids as the temperature increases in the solvent increases. 

 

Ammonia solutions decrease in density as the dissolved ammonia concentration increases. At 15.6 ° C (60.1 ° F), a saturated solution has a density of 0.88 g / ml and contains 35.6 percent ammonia by mass, 308 grams of ammonia per liter of solution, and molarity of about 18 mol / L.

 

The molarity of the saturated solution decreases at higher temperatures, and the density increases. The ammonia gas is released upon heating of saturated solutions.

 

Ammonium Hydroxide Uses

• Diluted ammonia (1–3 percent) is also a component of many cleaning agents, including many formulations for window cleaning.

• Aqueous ammonia may be used in industry as a precursor to certain alkyl amines, whereas anhydrous ammonia is usually preferred.

• The vapor absorption process became popular and widely used using the water-ammonia systems.

• Ammonia is used to make monochloramine, used as a disinfectant.

• Aquarians use ammonia to establish a new fish tank using ammonia, called fishless cycling. 

• Ammonia solution is used to treat straw and to produce “ammonia straw” which makes it more edible for cattle.

• Also used in the production of soaps, ceramics, detergents, inks and explosives, and pharmaceuticals.

• It is also used as an additive for maintaining a proper level of acidity in food.

• Ammonium hydroxide is also used as a refrigerant.

• Used in the manufacturing of rayon and other Textiles as well.

• Used as a purpose cleaner for surfaces like porcelain, glass, ovens, and stainless steel.

• It is also an effective antimicrobial agent due to its pH abilities.

• It is often used as a base in inorganic analysis and also as a complexant.

NH4OH Hazards

Health Hazards:

Inhalation, ingestion, or contact with material from the skin can cause serious injury or death. Contact with the molten material can cause severe skin and eye burns. Remove any touch to the skin. Touch or inhalation results may be adjourned. Fire can create gases that are irritating, corrosive, and/or toxic. Runoff from fire or dilution water can be corrosive and/or toxic, leading to pollution.

 

Fire Hazards:

Non-combustible, material does not burn itself but can decompose to create corrosive and/or toxic fumes when heated. Some are oxidizing agents and may ignite fuels (wood, paper, gasoline, clothes, etc). Metal contact can result in the formation of flammable hydrogen gas. Containers can explode when dry.

 

Conclusion

This is all about ammonium hydroxide, its physical and chemical properties. Focus on its features and how it is used in different aspects. Learn how it can be hazardous to our health. Understand why it is basic from its structural features.