Acids Bases and Salts Brainpop~Acids and Bases

Acid: A substance that releases H+ ions in an aqueous solution “ aqueous” means: water

Characteristics of Acids: Acids have a sour taste Acids react with metals Acids contain Hydrogen Many are poisonous and corrosive to skin H

Acids have a sour taste

Acids react with metals

Acids contain Hydrogen

Many are poisonous and corrosive to skin

Strong Acids (break down completely to give off many H+ ions)

Weak Acids (only partially breaks down, gives less H+) Mark Bishop Acid animation

Common Acids: All others considered Weak (examples) Acetic acid (vinegar) HC 2 H 3 O 2 Carbonic acid HCO 3 Weak Acid The Formula H 2 SO 4 HCl HBr HI HNO 3 HClO 4 Sulphuric acid Hydrochloric acid Hybrobromic acid Hydroiodic acid Nitric acid Perchloric acid The Formula Strong Acids

Base: A substance that releases OH- ions in an aqueous solution

Characteristics of Bases: Bases usually taste bitter Bases feel slippery Bases contain hydroxide ions STRONG bases are also poisonous and corrosive to skin OH -

Bases usually taste bitter

Bases feel slippery

Bases contain hydroxide ions

STRONG bases are also poisonous and corrosive to skin

Common Bases: (Hydroxides of Group 1 and Group 2 Metals are STRONG) All others are WEAK LiOH NaOH KOH RbOH CsOH Ba(OH) 2 Ca(OH) 2 Sr(OH) 2 Lithium hydroxide Sodium hydroxide Potassium hydroxide Rubidium hydroxide Caesium hydroxide Barium hydroxide Calcium hydroxide Strontium hydroxide The Formulae Strong Bases

Some bases (VERY FEW) don’t have OH- Most commonly: ammonia NH3

Reactions between acids and bases When and acid and a base react with each other, the characteristic properties of both are destroyed. This is called neutralization .

Reactions between acids and bases General formula for acid base reaction: Acid + Base -> H 2 O + Salt “ Salt” means any ionic compound formed from an acid/base reaction NOT JUST NaCl !! Neutralization Reaction Animation

Neutralization HCl + NaOH -> H 2 O + NaCl acid base water salt

Neutralization Another Example HNO 3 + KOH -> H 2 O + KNO 3 H OH K NO 3 acid base water salt

Indicators An indicator is a compound that will change color in the presence of an acid or base Universal indicator (pH paper) Used for the full pH range Red Litmus-Turns blue in base Blue Litmus-Turns red in acid Phenolphthalein-Turns pink in base

Universal indicator (pH paper) Used for the full pH range

Red Litmus-Turns blue in base

Blue Litmus-Turns red in acid

Phenolphthalein-Turns pink in base

pH pH stands for “potential hydrogen” and is a measure of how many H+ ions there are in solution. The MORE H+ there are, the LOWER the pH will be.

pH Scale Shows the range of H+ concentrations High H+ concentration Low H+ concentration