Calculator
Example Data Table
| Cation | Anion | Charges | Formula | Name | Approximate molar mass |
|---|---|---|---|---|---|
| Na | Cl | +1, -1 | NaCl | sodium chloride | 58.440 g/mol |
| Ca | NO3 | +2, -1 | Ca(NO3)2 | calcium nitrate | 164.086 g/mol |
| Al | SO4 | +3, -2 | Al2(SO4)3 | aluminum sulfate | 342.143 g/mol |
| Fe | O | +3, -2 | Fe2O3 | iron(III) oxide | 159.687 g/mol |
| Cu | SO4 | +2, -2 | CuSO4·5H2O | copper(II) sulfate pentahydrate | 249.683 g/mol |
Formula Used
The calculator reduces ion charges with the greatest common divisor. Cation subscript equals anion charge divided by that divisor. Anion subscript equals cation charge divided by that divisor.
Cation count = anion charge ÷ gcd. Anion count = cation charge ÷ gcd.
Molar mass = cation count × cation mass + anion count × anion mass + hydrate count × 18.01528.
Polyatomic ions receive parentheses when their subscript is greater than one. Hydrates add a centered dot and the water count.
How to Use This Calculator
- Select a cation and an anion from the lists.
- Adjust charge magnitudes when your problem gives a special valence.
- Enter custom ion symbols, names, and molar masses when needed.
- Add hydrate water molecules for hydrate compounds.
- Press the submit button to show the result above the form.
- Use the CSV or PDF option to save the result.
Naming Ionic Compounds With Confidence
Ionic names follow a clear pattern. The positive ion comes first. The negative ion comes second. A neutral formula must balance total charge. This calculator follows that rule before it builds a name. It also checks hydrate water, molar mass, and the simplest ion ratio.
Why Charge Balance Matters
Every ionic compound has no net charge. Sodium chloride works because sodium is plus one. Chloride is minus one. Calcium chloride needs two chloride ions. Calcium is plus two. Each chloride is minus one. The charge sum becomes zero. The same idea works for polyatomic ions. Parentheses are added when more than one polyatomic ion is needed.
Advanced Naming Support
Many metals have only one common charge. Sodium, calcium, aluminum, silver, and zinc are common examples. Some metals can use different charges. Iron, copper, tin, lead, mercury, and chromium often need Roman numerals. The calculator can show the cation charge in the name. That helps separate iron(II) chloride from iron(III) chloride. The formulas are different, and the names must show that difference.
Hydrates And Molar Mass
Hydrates include trapped water molecules. Copper(II) sulfate pentahydrate is a classic example. The dot in the formula separates the salt from water. The molar mass must include every water molecule. This page adds the hydrate contribution using the molar mass of water. It then reports the full value for one mole of the hydrate.
Useful Study Workflow
Use this tool when practicing nomenclature homework. Select known ions first. Adjust charges when your teacher gives a special oxidation state. Use custom ions for less common species. Check the formula, ratio, name, and mass together. Then export the result as a record. The example table shows how different charge pairs change subscripts. It also shows why parentheses appear around polyatomic ions.
Checking Your Result
Read the output in order. First check the charge sum. It should be zero. Next check each subscript. A subscript of one is hidden. Then review the compound name. The anion ending may change to ide for simple nonmetals. Polyatomic names usually stay unchanged. Finally compare molar mass with your notes. Small rounding differences are normal. Use the notes field to record class assumptions and teacher preferences clearly.
FAQs
What does this calculator name?
It names ionic compounds made from cations and anions. It also builds the neutral formula, checks charge balance, handles hydrates, and estimates molar mass.
Why do some ions need parentheses?
Parentheses are used for polyatomic ions when more than one copy is needed. Calcium nitrate becomes Ca(NO3)2 because two nitrate ions are required.
When should I use Roman numerals?
Use Roman numerals for metals with variable charges. Iron, copper, tin, lead, chromium, and mercury often need them in classroom naming rules.
Can I enter custom ions?
Yes. Choose custom cation or custom anion. Then enter the symbol, name, charge magnitude, molar mass, and polyatomic setting.
How is the formula balanced?
The tool reduces the two charge magnitudes by their greatest common divisor. Those reduced cross values become the smallest neutral subscripts.
Does it support hydrates?
Yes. Enter the number of water molecules. The tool adds the hydrate name, formula dot notation, and water mass contribution.
Is the molar mass exact?
It is an estimate based on stored atomic and ion masses. Use your required classroom periodic table when exact rounding rules matter.
Can I save the result?
Yes. After calculation, use the CSV button for spreadsheet records. Use the PDF button for a printable result summary.