Stage 1
Written by
Mr Ian Kershaw
Chemistry
BSc Dip Ed
The Author
Ian Kershaw B.Sc., Dip.Ed.
Ian has taught senior Chemistry since 1976. He was a member of the SSABSA Subject Advisory
Committee for some years in the 1990s. Ian has extensive experience, over 13 years, as a marker of
SACE Stage 2 examinations. He has taught in both metropolitan and country high schools and taught for
11 years in distance education. Ian is the author of the Stage 2 Chemistry Fundamentals Revision Guide
that has been developed over the past decade.
Publishing Information
This booklet is part 5 of a series of six Stage 1 booklets designed for the SACE Stage 1 Chemistry
course commencing in 2017 in South Australia.
This booklet is designed to complement other resources students may have in this particular
subject.
This Unit is published by Total Chemistry ABN 16632170634
ISBN
This booklet and others in the Stage 1 series were first published in 2016.
Copyright © Total Chemistry
Ian Kershaw email [email protected]
Copyright information
Unless permitted under the Copyright Act of 1968 (& subsequent amendments), no part of this
publication may be reproduced, stored in a retrieval system or transmitted in any form or by
any means without prior permission of the copyright owner.
The author has made every attempt to trace and acknowledge copyright. The author apologises
for any accidental infringement and would be quite happy to reach an amicable arrangement in
any such case.
SACE STAGE 1 CHEMISTRY
Unit 1.
Materials and their Atoms
1.1. Properties and uses of materials
1.2. Atomic structure
1.3. Quantities of atoms
1.4. The Periodic Table
Unit 2.
Combining Atoms
2.1. Types of materials
2.2. Bonding between atoms
2.3. Quantities
Unit 3.
Molecules
3.1. Molecular polarity
3.2. Interactions between molecules
3.3. Hydrocarbons
3.4. Polymers
Unit 4.
Mixtures and Solutions
4.1. Miscibility and solutions
4.2. Solutions of ionic substances
4.3. Quantities in reactions
4.4. Energy in reactions
Unit 5.
Acids and Bases
5.1. Acid-base concepts
5.2. Reactions of acids and bases
5.3. The pH scale
Unit 6.
Redox Reactions
6.1. Metal reactivity
6.2. Concepts of oxidation and reduction
6.3. Electrochemistry
Unit 5
Acids and Bases
Page
5.1.
5.2.
Acid-base concepts
3
Proton donors and acceptors
3
Equations with proton transfer
4
Conjugate acid-base pairs
4
Indicators
4
Mono and polyprotic acids
7
Reactions of acids and bases
9
Oxides of non-metals
9
Structural formula of oxides
10
Predict products given reactants
12
General reaction of acids & equations:
acids & metal oxides, hydroxides
and carbonates
acids & metals
12
Ionic equations
5.3.
12
13
12-13
Stoichiometry of acid/base reactions
14
Acid strength and ionisation
14
The pH scale
17
pH scale
17
pH = -log[H+]
18
pH calculations
18
CO2 and pH
19
Write equations for CO2 reactions
19
pH and oxides of S & N
Write equations for reactions of oxides of
S & N with water
Acid rain
20
Answers to Questions in notes
23
Questions
Solutions to Questions
25
Notes
39
Periodic Table
41
20
21
32
Unit 5. Acid -base concepts
5.1. Miscibility and solutions
Acids are compounds or ions that donate protons, whereas bases are compounds or ions
that accept protons, which are H+ ions.
The reactions between acids and bases can be represented using chemical equations that
illustrate the transfer of protons.

Write equations showing proton transfer between an acid and a base.

Identify the conjugate acid–base pairs given the equation for a proton transfer
reaction.
Acid-base indicators are weak acids or bases where the acidic form is of a different colour
from the basic form.
Acids can be classified as monoprotic or polyprotic, depending on the number of protons
available for donation.

Given the structural formula of an acid, classify it as monoprotic, diprotic, or
triprotic.
Water is a unique substance. It is a highly polar molecule and its
properties make it important in a range of chemical systems.
O
H
+
Water is a V-shaped molecule. The oxygen atom has four regions of
negative charge around it (electron pairs) that repel each other; two
are bonding pairs and two are non-bonding pairs; producing a
V-shaped molecule.
The two covalent bonds are highly polar due to the large
difference in electronegativity between oxygen and
hydrogen.
H
+
O
H
+
H
+
The two polar covalent bonds are not evenly distributed around the molecule, thus
creating a highly polar molecule.
An acid is defined as a substance (molecule or ion) that produces H+(aq) ions (or
hydronium ions, H3O+) in aqueous solution and are proton donors.
All acids contain hydrogen. For example, an acid HA:
+
H
The arrow show the direction of proton transfer.
This process of two molecules producing ions in solution is called ionisation.
Question: Write an equation, with an arrow showing the direction of proton
transfer, for the reaction between nitric acid, HNO3, and water. See page 23 for the
answer.
A base is the opposite of an acid. Bases can be defined as substances that will
produce hydroxide ions in aqueous solution and are receivers/acceptors of protons.
+
H
O2--(aq) + H2O(l)
OH--(aq) + OH--(aq)
+
H
NH3 + H2O
NH4+(aq) + OH--(aq)
The oxide ion, O2-, is a strong base as it reacts completely with water whereas
ammonia, NH3, is a weak base and only partially reacts in water. Note the use of
different equation arrows to represent the different extent of the reaction process.
+
H
HCl / Cl- are known as a conjugate acid-base pair. H3O+ / H2O make another
conjugate pair. The chloride ion, Cl-, is the conjugate base of HCl. Whereas HCl is the
conjugate acid of the chloride ion, Cl-.
Note: the acid is named first in an acid-base conjugate pair.
Question: Identify the acid- base conjugate pairs from the following equation:
See page for the answer
Acid-base indicators
The presence of acids and bases in solution can be identified by the use of acid-base
indicators. These indicators are substances that have the ability to change structure
depending on the concentration of hydrogen ions or hydroxide ions. A simple acidbase indicator is one that can exist in one of two different coloured forms
depending on the concentration of hydrogen ions present.