The key difference between ammonium sulfate and sodium sulphate is that ammonium sulfate has a pungent, irritating odour, whereas sodium sulphate is an odourless substance.
Ammonium sulfate and sodium sulfate contain sulfate anions bonded to different cations: ammonium cation and sodium cation. Therefore, these substances have different chemical and physical properties, as well.
Key Terms
1. Overview and Key Difference
2. What is Ammonium Sulfate
3. What is Sodium Sulphate
4. Side by Side Comparison – Ammonium Sulfate vs Sodium Sulphate in Tabular Form
6. Summary
What is Ammonium Sulfate?
Ammonium sulfate is an inorganic compound having the chemical formula (NH4)2SO4. This substance contains an ammonium cation linked to a sulfate anion. Therefore, it has two ammonium cations per sulphate anion. We can name this substance as an inorganic salt of sulfate with many important uses.
The molar mass of ammonium sulfate is 132.14 g/mol. This compound appears as fine, hygroscopic granules or crystals. Furthermore, the melting point of this compound can range from 235 to 280 °C; above this temperature range, the compound tends to decompose. We can produce ammonium sulfate compound by treating ammonia with sulfuric acid. For this preparation, we can use a mixture of ammonia gas and water vapour in a reactor. Also, we need to add concentrated sulfuric acid into this reactor, and then the reaction between these components will form ammonium sulfate.
Figure 01: Ammonium Sulfate Chemical Structure
When considering the applications of ammonium sulfate, we can use it as a fertilizer mainly for alkaline soils. Furthermore, we can use it in the production of insecticides, herbicides, fungicides, etc. In addition to these, we use this compound for the purification of protein via precipitation in the biochemistry laboratory. It is also useful as a food additive.
What is Sodium Sulphate?
Sodium sulphate is an inorganic compound having the chemical formula Na2SO4. This compound has several hydrated forms. Among them, the most common hydrate form is the decahydrate form. All anhydrous and hydrated forms occur as white crystalline solids. Furthermore, sodium sulphate is hygroscopic.
Figure 02: Chemical Structure of Sodium Sulphate
The molar mass of sodium sulphate is 142.04 g/mol (anhydrous form). It is odourless, and the melting point and boiling points are 884 °C and 1,429 °C. Therefore, this substance may have either orthorhombic or hexagonal crystal structures. More importantly, sodium sulphate is very stable. It is unreactive towards many oxidizing and reducing agents. However, at high temperatures, the substance can convert into sodium sulphide via carbothermal reduction.
Apart from that, this compound is a neutral salt. Therefore, the aqueous solution of this compound has a pH of 7. In addition to these, this compound can react with sulfuric acid giving the acid salt sodium bisulfate. When considering the applications of this compound, the decahydrate form is useful in manufacturing detergents and many other commodities. Moreover, it is important in the Kraft process and paper pulping.
What is the Difference Between Ammonium Sulfate and Sodium Sulphate?
Ammonium sulfate and sodium sulphate contain cations and anions bonded to each other; ammonium cation bonded to sulfate anion, and sodium cation bonded to sulfate anion. If we are given two samples of these compounds, we can easily distinguish between them by feeling their smell. The key difference between ammonium sulfate and sodium sulphate is that ammonium sulfate has a pungent, irritating odour, whereas sodium sulphate is an odourless substance.
The below infographic shows the differences between ammonium sulfate and sodium sulphate in tabular form for side by side comparison.
Summary – Ammonium Sulfate vs Sodium Sulphate
If we are given two samples of ammonium sulfate and sodium sulphate compounds, we can easily distinguish between them by feeling their smell. The key difference between ammonium sulfate and sodium sulphate is that ammonium sulfate has a pungent, irritating odour, whereas sodium sulphate is an odourless substance.
Reference:
1. “Ammonium Sulfate.” Wikipedia, Wikimedia Foundation, 21 Feb. 2021, Available here.
Image Courtesy
1. “Sodium sulfate” By Kemikungen – Own work (Public Domain) via Commons Wikimedia
2. “Ammonium sulfate” By Edgar181 – Own work (Public Domain) via Commons Wikimedia