Ammonium orthomolybdate, with the chemical formula (NH4)2MoO4, is a chemical compound composed of ammonium ions (NH4+) and molybdate ions (MoO4^2-). It is a white crystalline solid that is highly soluble in water.

Ammonium orthomolybdate has several key properties and uses, including:

1. Molybdenum Source: It is used as a source of molybdenum in various chemical reactions and processes.
2. Laboratory Reagent: Ammonium orthomolybdate is used as a laboratory reagent in certain chemical reactions and analyses.
3. Molybdenum Supplements: In some agricultural practices, ammonium orthomolybdate is used as a molybdenum supplement in fertilizers to provide essential molybdenum nutrients to plants.
4. Molybdenum Blue Test: It is used in analytical chemistry for the detection and determination of phosphates and other substances, known as the molybdenum blue test.

Ammonium orthomolybdate is generally considered safe to handle under normal conditions. However, like any chemical compound, it should be handled with care, and proper safety precautions should be followed to avoid unnecessary exposure.

As a source of molybdenum, ammonium orthomolybdate is valuable in various chemical processes and applications where molybdenum reactivity is needed. It finds uses in laboratory settings, agricultural practices, and as a reagent in chemical analyses.