Page 18 - [B._MURPHY,_C._MURPHY,_B._HATHAWAY]_A_working_meth

2 Chapter 1

STATES OF MATTER
Mutter is the chemical term for materials. There are three states of
matter: the solid phase (s), the liquid phase (1) and the gaseous phase
(g). In the solid phase, all the atoms or molecules are arranged in a
highly ordered manner [Figure 1,2(a)], whereas in the liquid phase
[Figure 1.2(b)], this ordered structure is not as evident. In the gaseous
phase [Figure 1.2(c)), all the particles are moving at high velocity, in
random motion. The disorder or entropy, S, is at its maximum in the
gaseous phase [Figure 1.2(c)].

(a) Solid (s) (b) Liquid (1) (c) Gas (g)

Increasing disorder or entropy, S

Figure 1.2 States of matter-solid, liquid and gas

If a species is dissolved in water, it is said to be in the aqueous
phase (aq), and the symbol can be represented as a subscript, e.g.
HCl(aq)*

ACIDS AND BASES
An acid is a proton (H+) donor and a base is a proton acceptor, e.g.
(OH-). Examples of acids include HCl, H2SO4, HN03, HCN and
CH3C02H. A monoprotic acid is an acid with one replaceable proton,
e.g. HCl (eA = 1); a diprotic acid is an acid with two replaceable
protons e.g. H2SO4 (eA = 2) etc., where eA is the number of reactive
species. A dilute acid is an acid which contains a small amount of acid
dissolved in a large quantity of water, whereas a concentrated acid is
an acid which contains a large amount of acid dissolved in a small
quantity of water.
Examples of bases include NaOH (eB = l), KOH (eB = l),
Ba(OH)2 (eB = 2), Ca(OH)2 (eB = 2), Mg(OH)2 (eB = 2), Na2C03
(eB = 2), NH3 and CH3NH2, where eB is the number of reactive