1. Acids and Bases

2. Acid Group of compounds with some common properties when in solution Group of compounds with some common properties when in solution 1 st – taste sour 1 st – taste sour 2 nd – change the color of certain dyes called indicators 2 nd – change the color of certain dyes called indicators 3 rd – most react with active metals to release hydrogen gas 3 rd – most react with active metals to release hydrogen gas

3. 4 th – acids react with bases to produce neutral salt and water 4 th – acids react with bases to produce neutral salt and water 5 th – acids conduct electric current 5 th – acids conduct electric current

4. Properties of Bases Bases taste bitter Bases taste bitter Feel slippery to the skin Feel slippery to the skin Bases change color of indicators Bases change color of indicators React with acid to form water and a salt React with acid to form water and a salt Are electrolytes Are electrolytes Excellent cleaning agents Excellent cleaning agents

5. Arrhenius Definition Acid ionize to form Acid ionize to form H + (H 3 O + ) Base ionize to form Base ionize to form OH - OH -

6. Bronsted Acid and Base Bronsted Acid – proton (H + ) donor Bronsted Acid – proton (H + ) donor Bronsted Base – proton acceptor Bronsted Base – proton acceptor NH 3 + H 2 O  NH 4 + + OH -

7. Bronsted definition is broader than Arrhenius – more things can be considered bases Bronsted definition is broader than Arrhenius – more things can be considered bases For each reaction identify the acid and base For each reaction identify the acid and base CH 3 NH 2 + H 2 O  CH 3 NH 3 + OH - CH 3 NH 2 + H 2 O  CH 3 NH 3 + OH - HSO 4 - + H 2 O  H 3 O + + SO 4 2- HSO 4 - + H 2 O  H 3 O + + SO 4 2-

8. Amphoteric In the last example we saw that water could act as either an acid or a base depending on what it reacted with In the last example we saw that water could act as either an acid or a base depending on what it reacted with Water is amphoteric – can act as either an acid or a base Water is amphoteric – can act as either an acid or a base

9. The strength of an acid (or base) is determined by the amount of IONIZATION.

10. Strong vs. Weak Acids Strong acid is one that ionizes completely Strong acid is one that ionizes completely HNO 3 (aq) ---> H + (aq) + NO 3 - (aq) HNO 3 (aq) ---> H + (aq) + NO 3 - (aq)

11. Weak acids are much less than 100% ionized in water. Weak acids are much less than 100% ionized in water. One of the best known is acetic acid = CH 3 CO 2 H One of the best known is acetic acid = CH 3 CO 2 H Weak Acids

13. Base Strength Any substance that ionizes completely to form OH - ions are strong bases Any substance that ionizes completely to form OH - ions are strong bases These solutions are said to be alkaline These solutions are said to be alkaline All highly soluble hydroxides are strong bases All highly soluble hydroxides are strong bases

14. Acid/Base Reactions Whenever an acid and base react, two conjugates are produced Whenever an acid and base react, two conjugates are produced Conjugate base – the species that remains after the acid has given up its proton Conjugate base – the species that remains after the acid has given up its proton Conjugate acid – the species that remains after the base has accepted the proton Conjugate acid – the species that remains after the base has accepted the proton