1. Gr. 10 Academic – Chemistry Mr. Findlay
Acid, Base & pH
Gr. 10 Academic – Chemistry
Mr. Findlay

2. ACIDS

3. Properties of Acids Dissolves in water, water soluble
Conduct electricity in aqueous solution
Corrosive (irritates & burns skin)
Taste sour
pH less than 7
Turn litmus paper red
Release hydrogen ions (H+) in aqueous solution
Corrode metals
Hydrogen first element in compound  binary acids & oxyacids
Reacts with metal  hydrogen gas
Reacts with carbonate compounds  CO2 gas

4. Naming Acids Binary acid – hydrogen + nonmetal
Ex. HCl (aq)– hydrochloric acid
“hydro” nonmetal “ic”
Acid
Oxyacid – hydrogen + oxyacid
Ex.H2SO4 (aq) – sulfuric acid
nonmetal “ic”
acid

5. Practice Naming Acids
HBr (aq)
H2CO3 (aq)
H3P (aq)
H3PO4 (aq)

6. BASES or ALKALI

7. Properties of Bases Dissolves in water
Conduct electricity in aqueous solution
Corrosive (irritate & burn skin)
Taste bitter
Feel slippery
pH greater than 7
Turns litmus paper Blue
Release hydroxide ions (OH-) in aqueous solution
Do not corrode metals

8. Naming Bases Metal + hydroxide ion For example: NaOH NH4OH Ca(OH)2
Mg(OH)2
*Note: not all bases will end in hydroxide

9. Acid-Base Indicators
Substances that change colour in acids or basic solutions
Can be used to make classify an unknown solution as an acid or a base
We look for changes to make a positive identification

11. Dissociation of Water

12. pH scale & the ions in solution

13. pH scale pH means “power of hydrogen”
Measurement is related to number of hydrogen ions in solutions
Indicates how acidic or basic a solution is
pH only determined when aqueous
pH scale is based on a logarithmic scale

15. Reading pH scale pH less than 7 is Acidic
The lower the pH, the more acidic
pH = 7 is Neutral
pH more than 7 is Basic
The higher the pH, the more basic

17. Lemon Juice is _______ times more acidic than milk.
Baking Soda is _______ times more basic than blood.
Stomach Acid (pH 2) is _______ times more acidic than seawater.

18. Acids & Bases in Food

19. Testing for pH: acid-base indicator
Litmus Paper – plant extract (red/blue) dried on strips of paper.
Litmus changes Blue = Base
Litmus changes Red = Acid
Does not change colour = Might be Neutral
Universal Indicator – chemical that changes colour through wide range of pH
pH meter – instrument that precisely measures pH of solution

20. pH of common substances using Litmus Paper

21. Universal Indicator

22. pH Meter Test voltage of electrolyte Converts voltage to pH
Very cheap & accurate
Must be calibrated with buffer solution