Select First/Second Cation and Anion pairs, and the Precipitation Reaction Predictor tells you whether mixing forms a precipitate — giving the Formula, Solubility Rule, Molecular Equation, and Net Ionic Equation.
Precipitation Prediction
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Complete Molecular Equation
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Net Ionic Equation
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Precipitate Formula
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Solubility Rule Applied
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A precipitation reaction occurs when two aqueous solutions of ionic compounds are mixed and an insoluble solid (precipitate) forms. This happens when the product of mixing has low solubility in water.
Solubility rules are guidelines that tell us which ionic compounds are soluble or insoluble in water. By applying these rules to the products of a double displacement reaction, we can predict if a precipitate will form.
Complete ionic equations show all ions present in solution, while net ionic equations only show the ions that participate in forming the precipitate. Spectator ions that don't react are omitted from net ionic equations.
Nitrates (NO₃⁻), acetates, and compounds containing alkali metals (Group 1) or ammonium (NH₄⁺) are generally always soluble in water according to solubility rules.
Most silver compounds are insoluble in water, except for silver nitrate and silver acetate. This makes silver ions excellent for precipitation reactions with halides and other anions.
Balance precipitation equations by ensuring equal numbers of each type of atom and equal charges on both sides. Start with the precipitate formula, then balance the spectator ions.