Name a supported ionic compound from its formula
The chemical name calculator recognizes a bounded classroom set of binary ionic compounds and salts containing common polyatomic ions. It identifies the cation first, identifies the anion second, uses subscripts to verify total charge, and adds a Roman numeral when a supported metal can have more than one oxidation state. The answer is shown with the ion names and charge balance so it can be checked rather than accepted as a guess.
Examples include sodium chloride, calcium hydroxide, iron(III) chloride, copper(II) sulfate, ammonium nitrate, and ammonium carbonate. Correct capitalization and subscripts matter: Co is cobalt, while CO would be carbon and oxygen. Formulas may contain up to 80 characters. Ordinary digits and Unicode subscripts are accepted, and parentheses may group a repeated polyatomic ion.
Fixed-charge and variable-charge cations
Group 1 metals, the supported group 2 metals, aluminium, zinc, cadmium, silver, and ammonium use a fixed classroom charge in this tool. Their names do not need Roman numerals. Iron, copper, cobalt, nickel, chromium, manganese, tin, and lead use a supported set of common positive oxidation states. The anion charge and formula subscripts determine which Roman numeral is required.
For Fe₂(SO₄)₃, three sulfate ions contribute a total charge of 6−. Two iron ions must therefore contribute 6+, so each iron is 3+ and the name is iron(III) sulfate. The calculation rejects a subscript pattern that would require a fractional cation charge or an oxidation state outside the stated set. That rejection is safer than returning a plausible-looking but unsupported name.
Monatomic and common polyatomic anions
Supported monatomic anions use the familiar -ide ending, including fluoride, chloride, bromide, iodide, oxide, sulfide, nitride, and phosphide. The polyatomic set includes hydroxide, nitrate, nitrite, sulfate, sulfite, carbonate, phosphate, acetate, hydrogen carbonate, cyanide, chromate, dichromate, chlorate, and perchlorate. Their established ion names are retained rather than rebuilt from element names.
Parentheses show that a polyatomic ion repeats as a unit. Ca(OH)₂ contains two hydroxide ions; writing CaOH₂ would describe a different element count and is rejected for naming. A single polyatomic ion may appear without parentheses, as in NaNO₃ or CuSO₄. The result prints the recognized cation and anion separately, making it easier to spot a formula that was typed differently from the exercise.
Why some formulas are deliberately rejected
Chemical nomenclature is much larger than simple ionic naming. Molecular compounds, acids, bases named as acids, hydrates, peroxides, coordination compounds, organometallic compounds, and systematic organic names require additional rules and sometimes structural information. A formula can also be ambiguous without oxidation state, connectivity, or phase context. This page does not send an unsupported formula to a language model or invent a name.
If the formula is rejected, first check capitalization, brackets, and subscripts. Then decide whether the compound actually belongs to the supported ionic set. A covalent formula such as CO₂ should be named with molecular-prefix rules, while an acid such as H₂SO₄ depends on acid nomenclature. Use a course reference or an appropriate specialist tool instead of forcing every formula through one rule.
Use the result as a learning check
Verify that total positive and negative charge cancel and that a Roman numeral describes cation charge, not the number of metal atoms. Read the formula back from the proposed name: combine the displayed ion charges in the smallest whole-number ratio and confirm the original subscripts. This two-way check catches many naming and formula-writing errors.
The values are calculated in the current browser tab. NexaCurrent does not upload the quantities, formulas, chemical names, element choices, or other information entered here, and no account is needed. Copying is a deliberate action after the answer and working are visible. Refreshing or leaving the page clears the current calculation, so keep a copied result if it is needed for later study.