Summary of Chapter 8 of the Chemistry for the IB Diploma Coursebook

8 ACIDS AND BASES


8.1 THEORIES OF ACIDS AND BASES
ACIDS BASES

Characteristics: Characteristics :

 Corrosive  Cleaning agents
 Hydrogen  Detergents
 Sour taste  Caustic / Corrosive
o citric acid- lemon  Slippery / soap



Examples :

- Bases : Oxides, NaOH
- Acids : HCl, NO3



BRØNSTED–LOWRY ACIDS AND BASES

The Brønsted–Lowry definition is:

 an acid is a proton (H+) donor
 a base/alkali is a proton (H+) acceptor

Ethanoic acid + Water ⇋ Ethanoate + Hydronium ION

Acid Base Base Acid




CONJUGATE ACID–BASE PAIRS ALWAYS DIFFER BY ONE PROTON (H+).

, AMPHIPROTIC AND AMPHOTERIC

Amphiprotic refers to species that can donate (acting as an acid) or accept (acting as a base) a
proton

Amphoteric is a more general term and refers to a substance that can act as an acid and a base



8.2 LEWIS ACIDS AND BASES (HL)
Lewis definition :

 An acid is an electron pair acceptor.
 A base is an electron pair donor.

A COORDINATE (DATIVE) COVALENT BOND IS ALWAYS FORMED IN A LEWIS ACID–BASE REACTION.

For a substance to act as a Lewis base, it must have a lone pair of electrons. For a substance to act
as a Lewis acid, it must have space to accept a pair of electrons in its outer shell



8.3 PROPERTIES OF ACIDS AND BASES

REACTION OF ACIDS AND BASES

ACIDS WITH METAL

Metal + Acid → Salt + Hydrogen

Unreactive metals such as copper do not react with dilute acids.



ACIDS WITH CARBONATES AND HYDROGENCARBONATES

Acid + Carbonate / Hydrogencarbonate → Salt + Carbon dioxide + Water



ACIDS WITH BASES AND ALKALIS

Base / Alkali + Acid → Salt + Water