1. Acids and Bases
Chapter 2.3 page 56

2. Acids
Acids release Hydrogen ions (H+) into aqueous solutions (water based). Egs include HCl – Hydrocholoric acid
Properties of acids include:
Produce Hydrogen ions
Are corrosive
Sour taste
Turn blue litmus red (red/burn)
React with some metals to produce Hydrogen gas and a salt
Conduct electricity
Are neutralized by bases producing water and a salt.

3. Strength of acids
Strong acids – most of the molecules release Hydrogen ions (H+) – Hydrochloric - HCl, Sulfuric, H2SO4, Nitric acid HNO3.
Weak acids – only some of the molecules release Hydrogen ions (H+) – Ascorbic (Vit C), acetic (vinegar), lactic acid (milk).

4. Bases and alkalis p 58
Bases release Hydroxide ions (OH-) eg soap the solution a base forms is known as an alkali or alkaline solution. Eg caustic soda, they burn just as badly as acids.
All bases share similar properties
They are caustic
Have a soapy slimy feel
Turn red litmus blue
Have a bitter taste
Conduct electricity
Are neutralized by acids producing water and a salt.

5. Strength of bases Strong bases form many Hydroxide ions (OH-)
eg NaOH Sodium Hydroxide – used in soaps and paint stripper.
Calcium Hydroxide
While weak base produce only a few
eg NaHCO3 - Sodium bicarbonate – baking soda
Sodium carbonate – washing powders

6. pH – potential of Hydrogen
Pure water has an exact balance of Hydrogen ions, and Hydroxide ions – pH 7.0
Acids have more hydrogen ions than hydroxide – (pH )
Bases have more hydroxide ions than hydrogen ions – (pH 7.1 – 14)
Human blood has pH of approx
Copy the adjacent list (colours optional)

7. Measuring pH - indicators
Indicators change colour in the presence of acids and bases. Litmus paper turns red in acids. Universal indicator can measure the numeric pH of the solution.

9. Checking understanding
Pearson interactive – page p 59
Chapter 2.3 Review Questions p , 2, 3, 5, 7, 8, 10, 16 in Full sentences.
Create a Frayer model – Acid