The key difference between aluminum sulfate and ammonium sulfate is that aluminum sulfate is a metal salt, whereas ammonium sulfate is an inorganic salt.
Aluminum sulfate is a metal salt having the chemical formula Al2(SO4)3, while Ammonium sulfate is an inorganic compound having the chemical formula (NH4)2SO4.
CONTENTS
1. Overview and Key Difference
2. What is Aluminum Sulfate
3. What is Ammonium Sulfate
4. Aluminum Sulfate vs Ammonium Sulfate in Tabular Form
5. Summary
What is Aluminum Sulfate?
Aluminum sulfate is a metal salt having the chemical formula Al2(SO4)3. This substance is water-soluble and is useful mainly as a coagulant agent during the purification of drinking water and in wastewater treatment plants. Moreover, this substance is useful in the paper industry.
Figure 01: Appearance of Aluminum Sulfate
There are both anhydrous forms and hydrated forms of aluminum sulfate. Naturally, the anhydrous form can be observed in a rare mineral named millosevichite. We can find this rare mineral in volcanic sites. However, the occurrence of the anhydrous form is very rare. There are different hydrates of aluminum sulfate, which include the hexadecahydrated forms as the most common hydrated form. Moreover, heptadecahydrate aluminum sulfate occurs naturally in the mineral alunogen.
The molar mass of anhydrous aluminum sulfate is 342.15 g/mo. It appears as a white crystalline solid that is highly hygroscopic. Sometimes, this substance is known as alum, or as papermaker’s alum according to different applications.
In a laboratory, we can produce aluminum sulfate through the addition of aluminum hydroxide to sulfuric acid or through the heating of aluminum metal in the presence of sulfuric acid. We can also produce this substance from alum schists which uses a mixture of iron pyrite, aluminum silicate and various bituminous substances.
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 compounds by treating ammonia with sulfuric acid. For this preparation, we can use a mixture of ammonia gas and water vapour in a reactor. In addition, we need to add concentrated sulfuric acid into this reactor, and then the reaction between these components will form ammonium sulfate.
Figure 02: The Chemical Structure of Ammonium Sulfate
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.
Difference Between Aluminum Sulfate and Ammonium Sulfate
Aluminum sulfate is a metal salt having the chemical formula Al2(SO4)3 while Ammonium sulfate is an inorganic compound having the chemical formula (NH4)2SO4. The key difference between aluminum sulfate and ammonium sulfate is that aluminum sulfate is a metal salt, whereas ammonium sulfate is an inorganic salt.
The following infographic lists the difference between aluminum sulfate and ammonium sulfate in tabular form.
Summary – Aluminum Sulfate vs Ammonium Sulfate
Aluminum sulfate is a metal salt having the chemical formula Al2(SO4)3, while Ammonium sulfate is an inorganic compound having the chemical formula (NH4)2SO4. The key difference between aluminum sulfate and ammonium sulfate is that aluminum sulfate is a metal salt, whereas ammonium sulfate is an inorganic salt.
Reference:
1. “Uses Of Aluminum Sulfate.” Aluminum Manufacturers.
Image Courtesy:
1. “Aluminium sulfate” Picture taken by Martin Walker in June 2005. (Public Domain) via Commons Wikimedia
2. “Ammonium sulfate” By Edgar181 – Own work (Public Domain) via Commons Wikimedia