1. Acids and Bases
Chem 332 – O’Dette

2. Let’s start with WATER!!!! H+ OH- Acid Part Base Part
When a water molecule splits, it forms two ions. H+
OH-
Acid Part
Base Part

3. Acid Base Theory Arrhenius
Svante Arrhenius in 1884 established the first theory of acids and bases
Acids produce H+ when dissolved in water
Bases produce OH- when dissolved in water
EX: HCl – acid NaOH – base

4. Acid Base Theory Bronsted-Lowry
Arrhenius theory doesn’t always work, for example NH3 would be considered an acid by Arrhenius theory but when NH3 reacts it will actually act as a base
In 1923 Johannes Bronsted and Thomas Lowry proposed a new acid base theory

5. Acid Base Theory Bronsted-Lowry (continued) Acid – proton (H+) donor
Base – proton (H+) acceptor
EX:
NH3 + H2O NH OH-
NH3 causes OH- to be generated so it is considered a base and accepted a proton (H+)

6. Strength of Acids & Bases
depends on dissociation
Dissociation = acid or base separates into ions in water
Acid Ex: HBr (aq) → H+ (aq) + Br- (aq)
Base Ex: KOH (aq) → K+(aq) + OH-(aq)
100% dissociation = strong acid/base

7. Strength of Acids & Bases
Strong Acids
Hydrochloric (HCl), Nitric (HNO3), Sulfuric (H2SO4)
Weak Acids
Citric (C6H8O7) & Carbonic (H2CO3)
Strong Bases
LiOH, NaOH, KOH
Weak Bases
Baking soda (NaHCO3) & Ammonia (NH3)

8. Properties of Acids & Bases
stingy
sour taste
turns litmus red
phenolphthalein = clear
universal indicator = red
bromthymol blue = yellow

9. Properties of Acids & Bases
soapy/slippery
chalky/bitter taste
turns litmus blue
phenolphthalein = pink
universal indicator = purple
bromthymol blue = blue