The key difference between ammonium hydroxide and sodium hydroxide is that ammonium hydroxide occurs in a liquid state while sodium hydroxide occurs in a solid-state at room temperature.
Although ammonium hydroxide and sodium hydroxide are –OH containing ionic compounds, they have different chemical and physical properties. This article looks at this difference between ammonium hydroxide and sodium hydroxide.
CONTENTS
1. Overview and Key Difference
2. What is Ammonium Hydroxide
3. What is Sodium Hydroxide
4. Side by Side Comparison – Ammonium Hydroxide vs Sodium Hydroxide in Tabular Form
5. Summary
What is Ammonium Hydroxide?
Ammonium hydroxide is a liquid having the chemical formula NH4OH. It is also an inorganic compound. We call it an ammonia solution because this compound forms when ammonia gas reacts with water. Therefore, we can denote it as NH3(aq). Though the name ammonium hydroxide implies the existence of an alkaline compound, it is actually impossible to isolate the chemical compound ammonium hydroxide.
Figure 01: Ammonia Solution
The molar mass of this compound is 35.04 g/mol, and it appears as a colourless liquid. This liquid has a highly pungent odour, and its boiling point is -57.5 ° C while the boiling point is 37.7 ° C. It is used as a household cleaner, as an alkyl amine precursor, for water treatment purposes, and many other applications.
What is Sodium Hydroxide
Sodium hydroxide is a metal hydroxide with the chemical formula NaOH. Most people know this substance as caustic soda. Sodium hydroxide is an ionic compound made of sodium cations (Na+) and hydroxide (OH–) anions. It is a strong base.
Figure 01: Sodium Hydroxide Pellets
The molar mass of sodium hydroxide is 39.99 g/mol. Sodium hydroxide is a solid at room temperature and appears as white, waxy crystals which are opaque. It is odourless. The melting point of sodium hydroxide is 318 °C, while the boiling point is 1,388 °C.
Since sodium hydroxide is a strongly basic compound, it can cause severe burns. Moreover, it is highly water-soluble. When dissolved in water, this ionic compound dissociates into its ions. This dissolution in water is highly exothermic. Sodium hydroxide is hygroscopic. This means, sodium hydroxide can absorb water vapour and carbon dioxide from the air when exposed to normal air.
The applications of sodium hydroxide include its use in the manufacturing of many soaps and detergents, manufacture of medicine such as aspirin, controlling water acidity, dissolving unwanted material in the wood when producing wood and paper products, etc.
What is the Difference Between Ammonium Hydroxide and Sodium Hydroxide?
Ammonium hydroxide and sodium hydroxide are two different inorganic compounds. Ammonium hydroxide is a liquid having the chemical formula NH4OH while sodium hydroxide is a metal hydroxide having the chemical formula NaOH. The key difference between ammonium hydroxide and sodium hydroxide is that ammonium hydroxide occurs in a liquid state while sodium hydroxide occurs in a solid-state at room temperature.
Moreover, another easily distinguishable difference between ammonium hydroxide and sodium hydroxide is that ammonium hydroxide has a fishy, pungent odour while sodium hydroxide is odourless.
Below is a summary of the difference between ammonium hydroxide and sodium hydroxide in tabular form.
Summary – Ammonium Hydroxide vs Sodium Hydroxide
Ammonium hydroxide is a liquid substance having the chemical formula NH4OH. Sodium hydroxide is a metal hydroxide having the chemical formula NaOH. The key difference between ammonium hydroxide and sodium hydroxide is that ammonium hydroxide occurs in a liquid state while sodium hydroxide occurs in a solid-state at room temperature.
Reference:
1. Helmenstine, Anne Marie. “How to Prepare a Sodium Hydroxide or NaOH Solution.” ThoughtCo, Aug. 28, 2020, Available here.
2. “Ammonium Hydroxide.” National Center for Biotechnology Information. PubChem Compound Database, U.S. National Library of Medicine, Available here.
Image Courtesy:
1. “Ammonia solution (25-28%)” By Leiem – Own work (CC BY-SA 4.0) via Commons Wikimedia
2. “Sodium hydroxide sample” By Nefronus – Own work (CC0) via Commons Wikimedia
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