2. Acid: A substance that releases H+ ions in an aqueous solution “ aqueous” means: water
3. Characteristics of Acids: <ul><li>Acids have a sour taste </li></ul><ul><li>Acids react with metals </li></ul><ul><li>Acids contain Hydrogen </li></ul><ul><li>Many are poisonous and corrosive to skin </li></ul>H
4. Strong Acids (break down completely to give off many H+ ions)
5. Weak Acids (only partially breaks down, gives less H+) Mark Bishop Acid animation
6. 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
7. Base: A substance that releases OH- ions in an aqueous solution
8. Characteristics of Bases: <ul><li>Bases usually taste bitter </li></ul><ul><li>Bases feel slippery </li></ul><ul><li>Bases contain hydroxide ions </li></ul><ul><li>STRONG bases are also poisonous and corrosive to skin </li></ul>OH -
9. 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
10. Some bases (VERY FEW) don’t have OH- Most commonly: ammonia NH3
11. 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 .
12. 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
13. Neutralization HCl + NaOH -> H 2 O + NaCl acid base water salt
14. Neutralization Another Example HNO 3 + KOH -> H 2 O + KNO 3 H OH K NO 3 acid base water salt
15. Indicators An indicator is a compound that will change color in the presence of an acid or base <ul><li>Universal indicator (pH paper) Used for the full pH range </li></ul><ul><li>Red Litmus-Turns blue in base </li></ul><ul><li>Blue Litmus-Turns red in acid </li></ul><ul><ul><ul><ul><ul><li>Phenolphthalein-Turns pink in base </li></ul></ul></ul></ul></ul>
16. 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.
17. pH Scale Shows the range of H+ concentrations High H+ concentration Low H+ concentration