Ammonium dihydrogen phosphate Ammonium dihydrogen phosphate Ammonium dihydrogen phosphate (ADP), commonly called monoammonium phosphate (MAP) is a chemical compound with formula . It is a white crystalline solid consisting of ammonium cations and dihydrogen phosphate anions in equal proportions. ADP is a major ingredient of agricultural fertilizers and some fire extinguishers. It also has significant uses in optics and electronics. Monoammonium phosphate is soluble in water and crystallizes from it as the anhydrous salt in the tetragonal system, as elongated prisms or needles. It is practically insoluble in ethanol. Solid monoammonium phosphate can be considered stable in practice for temperatures up to 200
Dihydrogen cation i because of the effect of the nuclear hyperfine Hamiltonian. The nuclear hyperfine Hamiltonian can mix the rotational levels of g and u electronic states (called ortho-para mixing) and give rise to ortho-para transitions The dihydrogen ion is formed in nature by the interaction of cosmic rays and the hydrogen molecule. An electron is knocked off leaving the cation behind. Cosmic ray particles have enough energy to ionize many molecules before coming to a stop. In nature the ion is destroyed by reacting with other hydrogen molecules: The ionization energy of the hydrogen molecule is 15.603 eV. The dissociation energy