Acids and Salts Bases Brainpop~Acids and Bases

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

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

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) Sulphuric acid Strong Acids The Formula Sulphuric acid Hydrochloric acid Hybrobromic acid Hydroiodic acid Nitric acid Perchloric acid H2SO4 HCl HBr HI HNO3 HClO4 All others considered Weak (examples) Weak Acid The Formula Acetic acid (vinegar) HC2H3O2 Carbonic acid HCO3

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

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

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

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 → Salt H2O + NOT JUST NaCl !! “Salt” means any ionic compound formed from an acid/base reaction Neutralization Reaction Animation

Neutralization HCl + NaOH → H2O + NaCl acid base water salt

Neutralization HNO3 + KOH → H2O + KNO3 H NO3 K OH Another Example acid base water salt

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

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