Find the species that change in an aqueous reaction
A net ionic equation calculator starts with a molecular equation whose species have explicit phases. It balances that equation, separates supported strong aqueous electrolytes into ions, writes the complete ionic equation, and cancels identical aqueous ions from both sides. The remaining equation highlights the species participating in precipitation, strong acid–base neutralization, or another supported classroom change.
Enter spaces around plus separators and mark every species as (aq), (s), (l), or (g). Phase matters because an aqueous strong electrolyte can dissociate while a precipitated solid, pure liquid, or gas remains intact. Unknown neutral aqueous compounds are rejected instead of guessed. You may enter an explicit charged aqueous ion using notation such as Ag+(aq) or SO4^2-(aq).
From molecular equation to complete ionic equation
The first step is ordinary mass and charge balance. The engine then consults a fixed rule table for common strong acids, strong bases, and soluble salts. For example, BaCl2(aq) becomes Ba^2+(aq) + 2Cl-(aq), while Na2SO4(aq) becomes 2Na+(aq) + SO4^2-(aq). BaSO4(s) remains a complete neutral solid formula.
The rule table is deliberately bounded and versioned. It does not treat every aqueous formula as fully dissociated, because weak acids, weak bases, complexes, ion pairs, and sparingly soluble substances require chemical context. Rejection is safer and more educational than inventing ions. If a compound is outside the table, enter a known complete ionic equation with explicit ions or use a more comprehensive equilibrium method.
Cancel spectator ions in a worked example
For BaCl2(aq) + Na2SO4(aq) → BaSO4(s) + 2NaCl(aq), the complete ionic form is Ba^2+ + 2Cl- + 2Na+ + SO4^2- → BaSO4(s) + 2Na+ + 2Cl-. Sodium and chloride appear unchanged with equal amounts on both sides, so they are spectator ions and cancel.
The resulting net ionic equation is Ba^2+(aq) + SO4^2-(aq) → BaSO4(s). Atom counts and net charge are conserved: the left charge is zero overall and the solid product is neutral. The cancellation table names exactly what was removed, allowing a learner to distinguish a spectator ion from an ion that disappears because it became part of a precipitate.
Check phases, coefficients, atoms, and charge
A valid net ionic equation must conserve every element and total charge. Coefficients should be reduced to the smallest whole-number ratio after cancellation. Do not cancel a species that changes phase, charge, formula, or coefficient. For example, Ag+(aq) and AgCl(s) are not identical species, even though both contain silver, so silver cannot be cancelled from a precipitation reaction.
Strong acid–strong base neutralization commonly reduces to H+(aq) + OH-(aq) → H2O(l). A weak acid normally remains molecular and needs rules beyond full strong-electrolyte dissociation. Redox equations may need electrons and balanced half-reactions. If all species cancel, the entered rules show no net change; review whether a reaction actually occurs or whether important chemistry was omitted.
Rule-table limits, safety, and privacy
This educational engine is not a universal solubility, speciation, or redox solver. Temperature, concentration, solvent, complex formation, acid strength, and ionic strength can change real behavior. Use verified solubility data, equilibrium constants, and a suitable chemical model for analytical work. A net ionic equation also does not establish mixing safety or authorize combining real reagents.
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.