Ammonium bisulfate, with the chemical formula (NH4)HSO4, is a chemical compound composed of ammonium ions (NH4+) and bisulfate ions (HSO4-). It is a white crystalline solid that is soluble in water.

Ammonium bisulfate has several key properties and uses, including:

1. pH Regulator: It is commonly used as a pH regulator and acidifier in various industries, including agriculture and water treatment. When added to water or soil, it releases hydrogen ions (H+) and sulfate ions (SO4^2-), which help to lower the pH and make the solution more acidic.
2. Fertilizer: Ammonium bisulfate is used as a nitrogen fertilizer in agriculture. It provides both ammonium ions and sulfate ions, which are essential nutrients for plant growth.
3. Metal Cleaning and Etching: In some industrial applications, ammonium bisulfate is used as a cleaning agent and etchant for metals.
4. Water Treatment: It is used in water treatment processes to adjust the pH of water and enhance the removal of impurities and metals.
5. Food Additive: Ammonium bisulfate is used as a food additive in certain food products. It is recognized as safe by regulatory authorities when used within specified limits.

Like other chemicals, ammonium bisulfate should be handled with care, and proper safety precautions should be followed when working with it. It is essential to store it in a cool, dry place away from incompatible substances to prevent hazardous reactions.

As a fertilizer and pH regulator, ammonium bisulfate plays a significant role in agriculture and water treatment. Its versatile applications in various industries make it an important chemical in the field of chemistry and technology.