How this calculator works
Select ions by either their symbol or name. Balance positive and negative charge using the smallest whole-number ion counts. Parentheses keep a repeated polyatomic ion together. Roman numerals identify the selected oxidation state. This educational tool constructs formal ionic formulas; charge balance alone does not establish stability, solubility or that a selected pair forms a real compound. Carbide here specifically means monatomic C4-, not acetylide C2(2-).
Formula
Cation count = anion charge magnitude / gcd(charges). Anion count = cation charge magnitude / gcd(charges). Total charge = 0.
Worked example
Ca2+ and OH- give Ca(OH)2, calcium hydroxide. Al3+ and SO4(2-) give Al2(SO4)3, aluminium sulfate.
Advertisement
Frequently asked questions
Why are parentheses added?
They show that a subscript applies to a complete polyatomic ion rather than its last atom.
What does iron(III) mean?
The Roman numeral identifies iron with oxidation state +3 in this ionic model.
Can this name organic molecules?
No. It covers the listed ionic building blocks, not general organic or coordination nomenclature.