1. Acids and Bases

2. Acids and Bases are types of compounds that have characteristic formulas and similar chemical behaviours, especially when they are dissolved in water.

3. HCl(aq)  H+(aq) + Cl-(aq)
Acids
Acids are substances that release H+ ions in water.
For Example,
HCl(aq)  H+(aq) + Cl-(aq)
aq = “aqueous”
Which means, “dissolved in water”

4. NaOH(aq)  Na+(aq)+ OH-(aq)
Bases
Bases are substances that release OH– ions in aqueous solution.
For Example,
NaOH(aq)  Na+(aq)+ OH-(aq)

5. Properties of Acids and Bases
Base (Alkali)
Feel
Taste
Formula
Example
Wet
(no characteristic feel)
Slippery
Sour
Bitter
Usually begins with hydrogen
HCl –hydrochloric acid
H2SO4 – sulfuric acid
HC3H5O – lactic acid
CH3COOH – acetic acid
Most bases contain the hydroxide ion (OH)
NaOH – sodium hydroxide
KOH – potassium hydroxide
NH3OH – ammonia hydroxide
K2SO3 – potassium sulfite
Vinegar, lemon juice
Baking soda, Oven cleaner

6. Measuring pH pH is measured on a scale from 1 to 14
1 to 7 = Acid (or acidic)
7 to 14 = Base (or basic)
pH of 7 (middle of scale) is neutral (like water)

7. Measuring pH The pH scale is logarithmic which means:
a pH of 1 is ten times more acidic than a pH of 2.

8. pH of some common substances
Acid
Neutral
Base
milk - 6.5
coffee – 5
tomatoes – 4
cola drinks – 3
stomach acid – 2
pure water – 7
blood sea water – 8 detergent – 10 household cleaners – 11 oven cleaners – 14

9. pH of substances can be measured using pH indicators.
pH paper
Universal Indicator
Natural indicators

10. pH paper

11. Universal Indicator

12. Natural Indicators

13. Acid + Base  Salt + Water
Neutralization
Acids and bases mix to form a salt and water
Acid + Base  Salt + Water
General Formula:
HxA B(OH)y  AB H2O
produces
H+ ions
produces
OH- ions
Lots of
types
HOH
(aka H2O)

14. Neutralization Examples:
Hydrochloric acid + Sodium hydroxide  Sodium chloride + Water
HCl + NaOH  NaCl + H2O
Nitric acid + Calcium hydroxide  Calcium nitrate + water
2HNO3 + Ca(OH)2  Ca(NO3)2 + 2H2O

15. Homework
Answer pg. 271 #2-6, 8
Read pg
Answer pg. 275 #2-5