ACIDS AND BASESACIDS AND BASES

What are some common acids What are some common acids that you have heard of?that you have heard of?

What are some common What are some common bases ?bases ?

Properties of Acids:Properties of Acids:

Sour-tastingWater-solubleGood conductors of electricity

When acids are dissolved in When acids are dissolved in water:water:

They release hydrogen ions (H+)Example:

(aq)–

(aq)(aq) Cl H HCl

Properties of Bases:Properties of Bases:

Bitter-tastingWater-solubleFeel slipperyGood conductors of electricity“alkaline”

When bases are dissolved in When bases are dissolved in water:water:

They release hydroxide ions (OH-)Example

(aq)-

(aq)(aq) OH Na NaOH

pH SCALEpH SCALE

http://library.thinkquest.org/3659/acidbase/ph.html

The pH (“power of hydrogen”)The pH (“power of hydrogen”)

Every 1 unit on the scale represents either an increase or decrease by a factor of 10

E.g. An acid with a pH of 4 is 10 times more acidic than an acid with a pH of 5

E.g. A base with a pH of 13 is 100 times more basic than a base with a pH of 11

CONCENTRATIONCONCENTRATIONOF ACIDS AND BASESOF ACIDS AND BASES

Amount of pure acid or base that is dissolved in 1 litre of water

Dilute vs. Concentrated

PERCENT IONIZATIONPERCENT IONIZATION

number of molecules of the acid or base that will ionize (form hydrogen or hydroxide ions) for every 100 molecules

Strong vs. Weak

Explain the following Explain the following statements:statements:

Sulfuric acid is stronger than acetic acid.

Katherine prepared two solutions of nitric acid, one dilute and one concentrated.

HomeworkHomework

Read pgs. 288-289; 293-298Pg 295 #3, 4Pg 299 #2-7

44a) From 12.5 to 10.5

2 pH more means 102 or 100 times as basic

b) From 12.5 to 8.5

4 pH more means 104 or 10 000 times as basic

3, 43, 4Name Formula Type

a) Potassium hydroxide KOH base

b) Hydrogen chlorate HClO3 acid

c) Magnesium hydroxide Mg(OH)2 base

d) Nitric acid HNO3 acid

e) Potassium bicarbonate KHCO3 base

22Name pH

a) A very concentrated base 13

b) A dilute basic solution 8

c) A very concentrated acid 1

d) A dilute acid solution 6

e) Tap water 7

33a) From 4.5 to 5.5

1 pH less means 10 times as acidic

b) From 4.5 to 6.5

2 pH less means 102 or 100 times as acidic

55a) Stomach acid (1.5) to tomatoes (4.0)

2.5 pH less means 102.5 or 100 to 1000 times as acidic

b) Lemon juice (2.0) to apples (3.0)

1 pH less means 10 times as acidic

66a) borax (9.1) to baking soda (8.2)

0.9 pH more means 100.9 or approximately 10 times as basic

b) bleach (12.4) to blood (7.3)

5.1 pH more means 105.1 or approximately 100 000 times as basic