1. Acids and Bases Introduction
Chem 12
Chapter 14 Pg

2. Properties of Acids Turn blue litmus paper red
Neutralize the properties of bases
React with certain metals to produce hydrogen gas
React with carbonate compounds to produce carbon dioxide gas
Have a sour taste
Are electrolytes
Have a pH less than 7

3. Properties of Bases Turn red litmus paper blue
Turn the indicator phenolphthalein from colorless to red
Neutralize the properties of acids
Have a bitter taste
Are electrolytes
Are slippery to the touch
Have a pH greater than 7

4. Common Acids Sulfuric Acid H2SO4 Nitric Acid HNO3
Phosphoric Acid H3PO4
Hydrochloric Acid HCl
Acetic Acid CH3COOH
Carbonic Acid H2CO3
Battery acid
Used to make fertilizers
and explosives
Food flavoring
Stomach acid
Vinegar
Carbonated water

5. Common Bases Name Formula Common Name
Sodium hydroxide NaOH lye or caustic soda
Potassium hydroxide KOH lye or caustic potash
Magnesium hydroxide Mg(OH)2 milk of magnesia
Calcium hydroxide Ca(OH) 2 slaked lime
Ammonia water NH3 H2O household ammonia .

6. Definition of Acid
An operational definition is a definition based on observed experimental properties.
An operational definition of an acid is that it is a substance that turns blue litmus paper red and has a pH less than 7.

7. An operational definition of a base is that it is a substance that turns red litmus paper blue and has a pH greater than 7.

8. A conceptual definition attempts to explain why a substance behaves the way it does.
Arrhenius theory (only applies to solutions made with water) and Bronsted-Lowery acid base definitions are conceptual

9. Arrhenius Acid-Base Theory
An acid is a substance that produces hydrogen ions, H+ (aq), in water. Hydrogen ions always combine with at least one water molecule to produce hydronium ions, H3O+
HCl(g) + H2O(l) < -- > H3O+ (aq) + Cl-(aq)
Arrhenius acid (hydrochloric acid)

10. NaOH(s) + H2O(l) → Na+ (aq) + OH-(aq)
Arrhenius Base
A base is a substance that produces hydroxide ions, OH- (aq), in water.
NaOH(s) + H2O(l) → Na+ (aq) + OH-(aq)
Arrhenius base (sodium hydroxide)

11. H3O+(aq) + OH-(aq) → 2H2O(l)
According to the Arrhenius acid-base theory, the hydronium ion explains the chemical properties of an acid, and the hydroxide ion explains the chemical properties of a base.
acid-base neutralization the hydronium ion from the acid reacts with the hydroxide ion from the base to produce water.
H3O+(aq) + OH-(aq) → 2H2O(l)

12. Brønsted-Lowry acid-base theory
An acid is proton (H+ ion) donor, and a base is a proton (H+ ion) acceptor.
This is a better definition because it is not limited to solutions where water is the solvent.
Acid (proton donor)
Base (proton acceptor)

13. Monoprotic Acids
Bronsted-Lowry acids can be monoprotic-capable of losing one proton, such as:
HCl(aq) + H2O(l)  H3O+(aq) + Cl-(aq)
HNO3(aq) + H2O(l)  H3O+(aq) + NO3-(aq)

14. Bronsted-Lowry acids can also be polyprotic-capable of losing (donating) more than one proton.
Polyprotic acids lose their protons in separate steps or reactions.

15. Diprotic Acids H2SO4(aq) + H2O(l)  HSO4-(aq) + H3O+(aq)
Diprotic acids are capable of losing two protons.
H2SO4(aq) + H2O(l)  HSO4-(aq) + H3O+(aq)
HSO4-(aq) + H2O(l)  SO42-(aq) + H3O+(aq)

16. Polybasic Bases
Bronsted-Lowry bases can be monobasic-capable of supplying one hydroxide ion such as
NaOH(s) + H2O(l)  Na+(aq) + OH-(aq)

17. Polybasic bases can be capable of supplying more than one hydroxide ion.
Dibasic are capable of supplying two hydroxide ions.
Mg(OH)2(s) + H2O(l)  Mg2+(aq) + 2OH-(aq)

18. Conjugate Acid-Base Pairs
A pair of substances that only differ by one proton.
Conjugate = “linked together”
H+ donor
NH4+ + CO3-2 < -- > NH HCO3-
Acid base conjugate conjugate
base acid

19. Conjugate acid and base, HA/A-, differ by one proton.
The conjugate acid of a base is the base plus the attached proton and the conjugate base of an acid
is the acid minus the proton.

20. Conjugate Acid-Base Pairs
Kelter, Carr, Scott, Chemistry A World of Choices 1999, page 280

21. Amphoteric
Substances that can act like an acid in one reaction, and like a base in another type of reaction.
Example: baking soda’s anion HCO3-
HCO3- + OH- < -- > CO3-2 + H2O (donates a H+, so acts like an acid)
HCO3- + H3O+ < -- > H2CO3 + H2O (accepts a H+, so acts like a base)

22. Practice:
Finish these questions for homework
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