# Net Ionic Equation Calculator - Molecular to Complete and Net Ionic Equations

> Free net ionic equation calculator: it balances the equation, splits strong electrolytes by solubility rules, cancels spectator ions and checks the charge.

- URL: https://qilingtools.com/en/math/net-ionic
- Category: Math Tools (https://qilingtools.com/en/math)
- Tags: [Math](https://qilingtools.com/en/tags/math), [Chemistry](https://qilingtools.com/en/tags/chemistry), [Education](https://qilingtools.com/en/tags/education)
- Last updated: 2026-10-26
- Price: Free, no sign-up
- Privacy: Runs locally in the browser; files are never uploaded

A net ionic equation shows only the species that actually change in a reaction in solution. To write one, balance the molecular equation, split every dissolved strong electrolyte — strong acids, strong bases and soluble salts — into its ions to get the complete ionic equation, then cancel the spectator ions that appear unchanged on both sides. For AgNO₃ + NaCl → AgCl + NaNO₃ the complete ionic equation is Ag⁺ + NO₃⁻ + Na⁺ + Cl⁻ → AgCl↓ + Na⁺ + NO₃⁻, so the net ionic equation is Ag⁺ + Cl⁻ → AgCl↓. Weak acids, insoluble solids, gases and water stay as formulas: CaCO₃ + 2HCl gives CaCO₃ + 2H⁺ → Ca²⁺ + H₂O + CO₂↑, and acetic acid with NaOH gives CH₃COOH + OH⁻ → CH₃COO⁻ + H₂O. This calculator balances your equation automatically, classifies every species with the solubility rules (backed by a Ksp table), dissociates salts correctly — Al₂(SO₄)₃ → 2Al³⁺ + 3SO₄²⁻, NaHCO₃ → Na⁺ + HCO₃⁻, NaHSO₄ → Na⁺ + H⁺ + SO₄²⁻ — and shows the molecular, complete ionic and net ionic equations side by side with spectator ions, precipitate and gas marks, and an atom and charge check. You can override how any species is written (for example a suspension or concentrated sulfuric acid). A second tab checks whether a set of ions can coexist in solution, flagging precipitates, gases, weak electrolytes, mutual hydrolysis, complex formation and redox pairs such as Fe³⁺/I⁻ or NO₃⁻/H⁺/Fe²⁺.

## How to use

1. Type a molecular equation (formulas only — coefficients are balanced for you) or pick a common reaction such as AgNO3 + NaCl or Cu + dilute HNO3
2. Read the molecular, complete ionic and net ionic equations, the spectator ions and the conservation check; change any species to “split into ions” or “keep formula” if needed
3. Switch to the ion compatibility tab, pick the ions and the acidic or basic condition, and see which pairs react and why

## Features

- Balances the equation automatically, then converts it to ionic form
- Classifies strong acids, strong bases, soluble salts, precipitates, weak electrolytes, gases, oxides and elements
- Built-in solubility rules plus a 25 °C Ksp table
- Handles acid salts correctly: HCO₃⁻ stays whole, HSO₄⁻ splits into H⁺ + SO₄²⁻
- Cancels spectator ions, reduces coefficients and marks precipitates and gases
- Checks atom and charge balance
- Per-species override for slightly soluble or concentrated reagents
- Ion compatibility checker covering precipitation, gas, weak electrolytes, hydrolysis, complexes, redox and coloured ions

## FAQ

### Which compounds are split into ions in a net ionic equation?

Only dissolved strong electrolytes: strong acids (HCl, HBr, HI, HNO₃, H₂SO₄, HClO₄, HClO₃), strong bases (LiOH, NaOH, KOH, Ba(OH)₂ and clear Ca(OH)₂ solution) and soluble ionic salts. Elements, oxides, insoluble precipitates, gases, weak acids and bases (CH₃COOH, HF, NH₃·H₂O), water and most organic compounds are written as formulas.

### What are spectator ions?

Spectator ions are ions that appear in the same form and amount on both sides of the complete ionic equation, so they take no part in the reaction. In NaOH + HCl → NaCl + H₂O the Na⁺ and Cl⁻ ions are spectators and the net ionic equation is H⁺ + OH⁻ → H₂O. If every ion cancels, as in NaCl + KNO₃, no reaction occurs.

### Why does the amount of reagent change the net ionic equation?

Some reactions go in steps. Adding a little HCl to sodium carbonate only protonates carbonate once: CO₃²⁻ + H⁺ → HCO₃⁻. With excess acid carbon dioxide is released: CO₃²⁻ + 2H⁺ → H₂O + CO₂. The tool includes both versions as presets so you can compare them; CO₂ bubbled into NaOH behaves the same way.

### How do I know if ions can coexist in solution?

Ions cannot coexist in large amounts if they react: forming a precipitate (Ba²⁺ + SO₄²⁻, Ag⁺ + Cl⁻), a gas (H⁺ + CO₃²⁻), a weak electrolyte (H⁺ + CH₃COO⁻, NH₄⁺ + OH⁻), undergoing mutual hydrolysis (Al³⁺ + HCO₃⁻), forming a complex (Fe³⁺ + SCN⁻) or a redox reaction (Fe³⁺ + I⁻, or NO₃⁻ with Fe²⁺ in acid). Remember hidden conditions: an acidic solution adds H⁺, a basic one adds OH⁻, and “colourless” rules out Cu²⁺, Fe³⁺, Fe²⁺ and MnO₄⁻.

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