What is Potassium Sulfate? - Structure, Uses & Formula - Video & Lesson Transcript

Potassium sulfate goes by other names, such as:

Its molecular formula is written as either:

In these formulas, the 'K' stands for potassium, the 'S' stands for sulfur, and the 'O' stands for oxygen. Visually, potassium sulfate can be represented via a 2D structure:

That being said, potassium sulfate would look radically different in real life. Potassium sulfate actually appears as a colorless or white powder or as colorless or white crystals. If you were to take a really close look at the crystals, they'd have a rhombic or hexagonal shape to them. If you decided to smell this compound you'd find that it doesn't really have a smell; and if you were to actually bite into it, you wouldn't like the experience and would probably regret it immediately. Potassium sulfate is hard, salty, and bitter.

Uses of Potassium Sulfate

Potassium sulfate can be made in one of several different ways. One way is to take potassium chloride and react it with sulfur dioxide, water, and oxygen to get potassium sulfate. Once it's made, potassium sulfate can be used in many different applications. However, its most famous and important use goes back to our introduction. It's used to help plants grow; in other words, it's a fertilizer.

A tobacco crop in Virginia

Potassium sulfate is the preferred fertilizer for specific kinds of crops, ones that do not tolerate fertilizers with chloride in them. Thus, it's used to help grow some types of fruits, vegetables, and tobacco. Locations where the soil is poor in both potassium and sulfur would turn to potassium sulfate as a fertilizer, such as in the Netherlands.

The muzzle flash of a revolver

Less commonly, but perhaps more interestingly, potassium sulfate is used for weapons applications. It's actually used as an inorganic flash suppressant. In other words, it's used to reduce a weapon's muzzle flash. By the way, inorganic means it's a compound that doesn't contain carbon atoms.

Potassium sulfate has also been used to help manufacture glass and abrasives.

Lesson Summary

Potassium sulfate is an inorganic chemical compound with a molecular formula of K2 SO4. It's also called dipotassium sulfate and sulfate of potash.

It's a colorless (or white), odorless, and bitter white powder or crystal. Its main use is as a fertilizer, especially for crops who cannot tolerate fertilizer with chloride in them, such as tobacco. It has also been used to help reduce muzzle flash, to manufacture glass, and to make abrasive compounds.