1. ACIDS AND BASES:
Strong and Weak

2. OUTCOME QUESTION(S):
C ACID/BASE AND pH
Outline acid/base theories and write acid/base equations. Include: Arrhenius, Bronsted-Lowry, Lewis.
Distinguish between strong and weak acids and bases. Include: electrolytes and non-electrolytes
Formulate an operational definition of pH and solve problems.
Vocabulary & Concepts 
polyprotic

3. This means the compound must dissociate or ionize in solution
For a solution to conduct an electric current, charged particles (ions) must be present.
C6H12O6
C6H12O6
This means the compound must dissociate or ionize in solution

4. as do highly polar molecules
Electrolytes: conduct an electric current when in aqueous solution or in a molten (melted) state.
All ionic compounds act as electrolytes
Most molecular compounds are non-electrolytes.
electrolytes
as do highly polar molecules
non-electrolytes
NaCl (s) Na+(aq) + Cl–(aq)
C6H12O6 (s) C6H12O6 (aq)

5. A (s) B+(aq) + C–(aq) A (s) B+(aq) + C–(aq)
Electrolytes are classified as strong OR weak:
Strong: produces many ions in solution.
dissociates 100% in water (NaCl)
A (s) B+(aq) + C–(aq)
Equilibrium can favour the forward or reverse reaction
– this determines how many electrolytes are in solution
Weak: partially dissociates (<<100%) in solution.
usually weak polar molecules (vinegar)
A (s) B+(aq) + C–(aq)

6. polar
ionic
You should be able to identify polar and ionic compounds from the formula
ionic
polar

7. HCl (l) + H2O H+(aq) + Cl–(aq) Strong acids are strong electrolytes
easily donate protons
completely dissociate or ionize
[acid] initially will equal [H+] at equilibrium (think of an ICE table)
HCl (l)
+ H2O
H+(aq) + Cl–(aq)
Indicate complete dissociation using single arrow and simplifying the equation by ignoring water
Common Strong Acids
Formula
perchloric acid
HClO4
hydrochloric acid
HCl
sulfuric acid
H2SO4
nitric acid
HNO3
hydroiodic acid HI
hydrobromic acid
HBr

8. HC2H3O2 + H2O H3O+ + C2H3O2- Weak acids are weak electrolytes
poorly donate protons
incompletely dissociate or ionize
equilibrium favors reverse reaction – ions regroup quickly
HC2H3O2 + H2O H3O+ + C2H3O2-
Indicate incomplete dissociation and equilibrium reached by using reversible arrow and including water
Common weak Acids
Formula
carbonic acid
H2CO3
hydrofluoric acid HF
acetic acid
CH3COOH
phosphoric acid
H3PO4
There are many weak acids and they are listed on your acid strength chart

9. Relative Strength of Acids
Strongest
Why would the strong acids have Ka without measurable values?
Weakest

10. An acid that contains more than one ionizable hydrogen is called polyprotic.
Two – diprotic
Only one – monoprotic
Phosphoric acid H O s p H O s
Each hydrogen ion has a unique affinity for ionizing which creates unique equilibrium values Cl H
Sulfuric acid

11. Strong bases create hydroxide (OH1-) or oxide (O2-) ions
Strong bases are strong electrolytes
easily accept protons
completely dissociate or ionize
[base] initially will equal [OH-] at equilibrium
NaOH (s) Na+(aq) + OH–(aq)
Common Strong Bases
Formula
barium hydroxide
Ba(OH)2
strontium hydroxide
Sr(OH)2
lithium hydroxide
LiOH
potassium hydroxide
KOH
Strong bases create hydroxide (OH1-) or oxide (O2-) ions
Basically, any Alkali (I) or Alkali Earth (II) metal hydroxide would be a strong base

12. Weak bases are typically related to strong acids…
Weak bases are weak electrolytes
poorly accept protons
incompletely dissociate or ionize
equilibrium favors reverse reaction – ions regroup quickly
NH3(g) + H2O (l) NH4+(aq) + OH-(aq)
Indicate incomplete dissociation and equilibrium reached by using reversible arrow and including water
Common weak Bases
Formula
carbonate ion
CO32-
alanine
C3H5O2NH2
pyridine
C5H5N
methylamine
CH3NH2
Weak bases are typically related to strong acids…

13. Common weak bases are usually conjugate bases of strong acids.
HA H2O
H3O A-
Con. acid
Con. base
acid
base
Logic: for a strong acid - the forward reaction is favoured because it is a poor base in the reverse reaction
The stronger the A/B, the weaker its conjugate.
The weaker the A/B, the stronger its conjugate.

14. This side contains the conjugate bases of the acids
Strongest
Weakest
This side contains the conjugate bases of the acids
Note: these are all still “weak” bases as there are no strong metal hydroxides here
BASES
Stronger
Weakest

15. forward reaction is favoured
The equilibrium reaction favours the strongest acid:
HSO HTe-
H2Te + SO42-
acid
base
Con. acid
Con. base
Use the acid strength table to evaluate the two acids of the equation – the acid with the larger Ka value is the stronger acid and will dominate the reaction
forward reaction is favoured
HSO4– is the stronger acid

16. Reverse reaction is favoured
Which direction is favoured at equilibrium?
HCO PO43-
CO HPO42-
acid
base
Con. acid
Con. base
Hydrogen carbonate ion is higher than hydrogen carbonate ion
Reverse reaction is favoured
HCO31- is the stronger acid

17. CAN YOU / HAVE YOU?
C ACID/BASE AND pH
Outline acid/base theories and write acid/base equations. Include: Arrhenius, Bronsted-Lowry, Lewis.
Distinguish between strong and weak acids and bases. Include: electrolytes and non-electrolytes
Formulate an operational definition of pH and solve problems.
Vocabulary & Concepts 
polyprotic