Ammonium chloride, commonly known as sal ammoniac, exists in both white and blue forms. The difference between white and blue ammonium chloride lies in their crystal structures and the presence of impurities.
White Ammonium Chloride: White ammonium chloride is the more common form of ammonium chloride. It has a crystalline structure with a cubic or hexagonal shape. The white color of this form is due to the absence of impurities. It is often used in various applications, including as a flux in soldering, in dry cell batteries, as a nitrogen source in fertilizers, and in the pharmaceutical industry.
Blue Ammonium Chloride: Blue ammonium chloride, also known as blue salt or sapphire salt, is a less common form of ammonium chloride. It gets its name from its distinctive blue color. The blue color arises due to the presence of small amounts of copper(II) chloride (CuCl2) impurities in the crystal lattice of ammonium chloride. The copper impurities can be introduced during the production process or as a result of environmental factors. Blue ammonium chloride is sometimes used for decorative purposes or as an ingredient in certain chemical experiments or demonstrations.
It's important to note that blue ammonium chloride is not a naturally occurring form but rather a variation resulting from impurities. The majority of commercially available ammonium chloride is in the white form. The presence of impurities can affect the properties and potential applications of the compound, but in general, the distinction between white and blue ammonium chloride lies primarily in their appearance rather than in their fundamental chemical properties.