A chemical reaction in which water is formed by mutual interaction of the ions that characterize acids and bases when both are present in an aqueous solution, i.e., H+ + OH− → H2O, the remaining product being a salt. R. T. Sanderson states: “An aqueous solution containing an excess of hydronium ions is called acidic. It readily releases protons to electron-donating substances. An aqueous solution containing an excess of hydroxyl ions is called basic. It readily accepts protons from substances that can release them, and is in general an excellent donor. No aqueous solution can contain an excess of both hydronium and hydroxyl ions, because when these ions collide, a proton is immediately transferred from the hydronium to the hydroxyl ion, and both become water molecules.”Neutralization occurs with both (1) inorganic and (2) organic compounds: (1) Ca(OH)2 + H2SO4 → CaSO4 + 2H2O; (2) HCOOH + NaHCO3 → HCOONa + CO2 + H2O. It should be noted that neutralization can occur without formation of water, as in the reaction CaO + CO2 → CaCO3. Neutralization does not mean the attaining of pH 7.0; rather it means the equivalence point for an acid-base reaction. When a strong acid reacts with a weak base, the pH will be less than 7.0, and when a strong base reacts with a weak acid, the pH will be greater than 7.0.
