Polyatomic Ion Calculator

A polyatomic ion, also known as a molecular ion, is a charged species (ion) composed of two or more atoms covalently bonded or of a metal complex that can be considered as acting as a single unit in the context of acid and base chemistry or in the formation of salts. By putting the positive ion and the negative ion in the respective boxes, you can find the scientific name of that polyatomic. In an ionic compound, electrons are transferred to atoms and molecules imparting a charge on both the donor and recipient of the electron.
Polyatomic Ion
Positive Ion:
Negative Ion:
Result:
Formula
When you write the formula for an ionic compound, remember that the positive ion is always listed first. When there are two or more polyatomic ions in a formula, enclose the polyatomic ion in parentheses. Write down the information you have for the charges of the component ions and balance them to answer the problem.

Polyatomic Ion Charge = -1
acetate - C2H3O2-
bicarbonate (or hydrogen carbonate) - HCO3-
bisulfate (or hydrogen sulfate) - HSO4-
chlorate - ClO3-
chlorite - ClO2-
cyanate - OCN-
cyanide - CN-
dihydrogen phosphate - H2PO4-
hydroxide - OH-
nitrate - NO3-
nitrite - NO2-
perchlorate - ClO4-
permanganate - MnO4-
thiocyanate - SCN-

Polyatomic Ion Charge = -2
carbonate - CO32-
chromate - CrO42-
dichromate - Cr2O72-
hydrogen phosphate - HPO42-
peroxide - O22-
sulfate - SO42-
sulfite - SO32-
thiosulfate - S2O32-

Polyatomic Ion Charge = -3
borate - BO33-
phosphate - PO43-

A polyatomic ion considers two or more atoms at a time as constituents. Polyatomic ions consist of multiple atoms that combine with other ions to form an ionic compound.
The hydroxide cation (OH-) and the phosphate cation (PO43-) are both polyatomic ions.

Example:
Barium has a +2 charge and hydroxide has a -1 charge, therefore
1 Ba2+ ion is required to balance 2 OH- ions Ammonium has a +1 charge and phosphate has a -3 charge, therefore
3 NH4+ ions are required to balance 1 PO43- ion Potassium has a +1 charge and sulfate has a -2 charge, therefore
2 K+ ions are required to balance 1 SO42- ion

Answer
1. Ba(OH)2
2. (NH4)3PO4
3. K2SO4

Example:
Calculate the polyatomic ion for the given positive and negative ions.
Positive ion = Li
Negative ion = Cl

Solution:
Therefore the polyatomic ion for the above positive and negative ions is Lithium Chloride.