And Neutralization

Acidic or basic is a chemical property Mixing them can cancel out their effects or neutralize them But 1st-water ionizes Water molecules exist in equilibrium with hydrogen ions and hydroxide ions. H 2 O H + + OH -

If an acid (H + ) is added to water, the equilibrium shifts to the left and the OH - ion concentration decreases. Water Equilibrium: H 2 O H + + OH - If base ( OH - ) is added to water, the equilibrium shifts to right and the H + concentration decreases.

BOTH H + and OH - ions are ALWAYS PRESENT in any solution. A solution is acidic if the H + are in excess. A solution is basic, if the OH - ions are in excess.

Neutralization is the reaction between an acid and a base that produces a salt and water. A salt is an ionic compound that is composed of a cation from a base and an anion from an acid.

In the reaction of an acid with a base in aqueous solution, the hydrogen ions of the acid react with the hydroxide ions of the base to give water. The 2nd product is a salt.

A salt is made of the positive metal ion from the base and the negative ion from the acid. For example, HCl + NaOH → NaCl + H 2 O HCl + KOH → H2O + KCl

HCl + NaOH → NaCl + H 2 O HCl + KOH → H2O + KCl

pH is measured using a logarithmic scale The water equilibrium constant is written as: Kw = [H + ] [OH - ] Therefore: Kw = [10 -7 ][ ] = [ ]