Topic 7 - The Chemistry and Uses of Acids, Bases and Salts

7.1 The characteristic properties of acids and bases
(a) describe the meanings of the terms acid and alkali in terms of the ions they contain or produce in aqueous solution and their effects on Universal Indicator paper

(b) describe how to test hydrogen ion concentration and hence relative acidity using Universal Indicator paper and the pH scale

(c) describe the characteristic properties of acids as in reactions with metals, bases and carbonates
(d) describe qualitatively the difference between strong and weak acids in terms of the extent of ionisation

(e) describe neutralisation as a reaction between hydrogen ions and hydroxide ions to produce water, H⁺ + OH^– → H₂O

(f) describe the importance of controlling the pH in soils and how excess acidity can be treated using calcium hydroxide
(g) describe the characteristic properties of bases in reactions with acids and with ammonium salts
(h) classify oxides as acidic, basic or amphoteric, based on metallic/non-metallic character
7.2 Preparation of salts

(a) *describe the techniques used in the preparation, separation and purification of salts as examples of some of the techniques specified in Section 1.2(a)
(methods for preparation should include precipitation and titration together with reactions of acids with metals, insoluble bases and insoluble carbonates)

(b) describe the general rules of solubility for common salts to include nitrates, chlorides (including silver and lead), sulfates (including barium, calcium and lead), carbonates, hydroxides, Group I cations and ammonium salts

(c) suggest a method of preparing a given salt from suitable starting materials, given appropriate information

7.3 Properties and uses of ammonia

(a) describe the use of nitrogen, from air, and hydrogen, from cracking oil, in the manufacture of ammonia

(b) state that some chemical reactions are reversible (e.g. manufacture of ammonia)

(c) *describe and explain the essential conditions for the manufacture of ammonia by the Haber process

(d) describe the use of nitrogenous fertilisers in promoting plant growth and crop yield

(e) compare nitrogen content of salts used for fertilisers by calculating percentage masses

(f) describe eutrophication and water pollution problems caused by nitrates leaching from farm land and explain why the high solubility of nitrates increases these problems

(g) describe the displacement of ammonia from its salts and explain why adding calcium hydroxide to soil can cause the loss of nitrogen from added nitrogenous fertiliser

7.4 Sulfuric acid

(a) describe the manufacture of sulfuric acid from the raw materials sulfur, air and water in the Contact process

(b) state the use of sulfur dioxide as a bleach, in the manufacture of wood pulp for paper and as a food preservative (by killing bacteria)

(c) state the uses of sulfuric acid in the manufacture of detergents and fertilisers, and as a battery acid

Bonding

2.4 Ionic bonding
(a) *describe the formation of ions by electron loss/gain in order to obtain the electronic configuration of an inert gas
Read p87-92
(b) *describe the formation of ionic bonds between metals and non-metals, e.g. NaCl; MgCl₂
Read p93-94

(c) *state that ionic materials contain a giant lattice in which the ions are held by electrostatic attraction, e.g. NaCl (candidates will not be required to draw diagrams of ionic lattices)
Read p96
(d) deduce the formulae of other ionic compounds from diagrams of their lattice structures, limited to binary compounds
Read p94-95
(e) relate the physical properties (including electrical property) of ionic compounds to their lattice structure
Read p97-99

2.5 Covalent bonding
(a) *describe the formation of a covalent bond by the sharing of a pair of electrons in order to gain the electronic configuration of an inert gas
Read p102

(b) describe, using ‘dot-and-cross’ diagrams, the formation of covalent bonds between non-metallic elements, e.g. H₂; Cl₂; O₂; HCl; N₂; H₂O; CH₄; C₂H₄; CO₂
Read p102-105
(c) deduce the arrangement of electrons in other covalent molecules
Read p106
(d) relate the physical properties (including electrical properties) of covalent compounds to their structure and bonding
Read p106-112

2.6 Metallic bonding
(a) *describe metals as a lattice of positive ions in a ‘sea of electrons’
Read p113

(b) *relate the malleability of metals to their structure and the electrical conductivity of metals to the mobility of the electrons in the structure
Read p113

Topic 2 - The Particulate Nature Of Matter

2.1 Kinetic particle theory
(a) *describe the solid, liquid and gaseous states of matter and explain their interconversion in terms of the kinetic particle theory and of the energy changes involved
Read p1-15
(b) *describe and explain evidence for the movement of particles in liquids and gases (the treatment of Brownian motion is not required)
Read p16-20
(c) explain everyday effects of diffusion in terms of particles, e.g. the spread of perfumes and cooking aromas; tea and coffee grains in water
Read p16-20
(d) *state qualitatively the effect of molecular mass on the rate of diffusion and explain the dependence of rate of diffusion on temperature
Read p16-20
(e) state qualitatively and explain the effects of temperature and pressure on the volumes of gases
Read p16-20
2.2 Atomic structure
(a) state the relative charges and approximate relative masses of a proton, a neutron and an electron
Read p74-77
(b) *describe, with the aid of diagrams, the structure of an atom as containing protons and neutrons (nucleons) in the nucleus and electrons arranged in shells (energy levels) (no knowledge of s, p, d and f classification will be expected; a copy of the Periodic Table will be available in Papers 1 and 2)
Read p76-77,79 
(c) define proton number and nucleon number Read p76
(d) interpret and use symbols such as ¹²₆C  Read p77
(e) define the term isotopes Read p78
(f) deduce the numbers of protons, neutrons and electrons in atoms and ions from proton and nucleon numbers Read p76-77
(g) state that some isotopes are radioactive Read p78

2.3 Structure and properties of materials
(a) describe the differences between elements, compounds and mixtures
Read p59-71
(b) *compare the structure of simple molecular substances, e.g. methane, iodine, with those of giant molecular substances, e.g. sand, diamond, graphite in order to deduce their properties
Read p106-110
(c) *compare the bonding and structures of diamond and graphite in order to deduce properties such as electrical conductivity, lubricating or cutting action (candidates will not be required to draw the structures)
Read p109-110
(d) deduce the physical and chemical properties of substances from their structures and bonding and vice versa

Topic 1 - Experimental Chemistry

It is expected that any course in chemistry will be based on experimental work. Teachers are encouraged to develop appropriate practical work for candidates to facilitate a greater understanding of the subject.

Candidates should be aware of the hazards and appropriate safety precautions to follow when handling the reagents mentioned in this section.

1.1 Experimental design
(a) name appropriate apparatus for the measurement of time, temperature, mass and volume, including burettes, pipettes, measuring cylinders and gas syringes
CM - Chapter 2 p23-29
Read the textbook and underline important points using the objective.
Watch the video clips which follow.

(b) suggest suitable apparatus, given relevant information, for a variety of simple experiments, including collection of gases and measurement of rates of reaction
CM - Chapter 2 p26-27
Read the textbook and underline important points using the objective
1.2 Methods of purification and analysis
(a) describe methods of purification by the use of a suitable solvent, filtration and crystallisation, distillation and fractional distillation, with particular references to the fractional distillation of crude oil, liquid air and fermented liquor
CM - Chapter 3 p40-54,
Crystallisation

Distillation - Watch the video clip

Fractional distillation

A little history of petroleum - in French

Fractional distillation - p381(crude oil),

p51(liquid air), p418 (fermented liquor).
Read the textbook and underline important points using the objective
You are explicitly asked not to imitate the character in the following video clip

(b) suggest suitable methods of purification, given information about the substances involved
CM - Chapter 3 p52 - Key ideas
(c) describe paper chromatography and interpret chromatograms including 
comparison with ‘known’samples and the use of Rf values
CM - Chapter 3 p36-39
Watch the video clip

(d) explain the need to use locating agents in the chromatography of colourless compounds
CM - Chapter 3 p39
Watch the video clip.

(e) deduce from the given melting point and boiling point the identities of substances and their purity
CM - Chapter 3 p32-35
Watch the following video clip

(f) explain that the measurement of purity in substances used in everyday life, e.g. foodstuffs and drugs, is important

CM - Chapter 3 p33

1.3 Identification of ions and gases
(a) describe the use of aqueous sodium hydroxide to identify the following aqueous cations: aluminium, ammonium, calcium,  chromium(III),  copper(II), iron(II), iron(III) and zinc (formulae of complex ions are not required)

CM - Chapter 12 p205 - 206
Watch the video clips

Analysis of calcium ions

and aqueous ammonia to identify the following  aqueous cations: aluminium, ammonium, calcium, chromium (III), copper(II), iron(II), iron(III) and zinc (formulae of complex ions are not required)

CM - Chapter 12 p205 -206

Watch the video clip

(b) describe tests to identify the following anions: carbonate (by the addition of dilute acid and subsequent use of limewater); chloride (by reaction of an aqueous solution with nitric acid and aqueous silver nitrate); iodide (by reaction of an aqueous solution with 
nitric acid and aqueous silver nitrate); nitrate (by reduction with aluminium and aqueous sodium hydroxide to ammonia and subsequent use of litmus paper) and sulfate (by reaction of an aqueous solution with nitric acid and aqueous barium nitrate)
CM - p 207
Watch the following video clips

Analysis of iodide ions

(c) describe tests to identify the following gases: 

ammonia (using damp red litmus paper); 
carbon dioxide (using limewater); 
chlorine (using damp litmus paper); 
hydrogen (using a burning splint); 
oxygen (using a glowing splint) and 
sulfur dioxide (using acidified potassium dichromate(VI))

(d) describe a chemical test for water

Welcome To The Chemistry Blog

First things first.
You will have to become familiar with your syllabus - code number 5070 for 2014. You will need it for study and revision purposes
Click here to view and download it.
I hope you will enjoy the time you spend here to learn the subject, but also become familiar with learning online.

Assessment at a glance
For the Cambridge O Level in chemistry, candidates take three components: Paper 1 and Paper 2 and  Paper 4.
Paper 1: Multiple Choice 1 hour
40 compulsory multiple-choice questions. A copy of the Periodic Table is provided as part of this paper. 40 marks

Paper 2: Theory 1 hour 30 minutes
This paper has two sections.
Section A has a small number of compulsory, structured questions of variable 
mark value. 45 marks in total are available for this section.
Section B has four questions to choose from and candidates must answer three. Each question is worth 10 marks.
A copy of the Periodic Table is provided as part of this paper. 75 marks

Paper 4: Alternative to Practical 1 hour
A written paper of compulsory short-answer and structured questions designed to test familiarity with laboratory practical procedures.
Qualitative Analysis Notes are not provided. 
60 marks scaled to a mark out of 30
Textbook used: GCE 'O' Level Chemistry Matters - Tan Yin Toon, Chen Ling Kwong, John Sadler, Emily Clare (Marshall Cavendish)
In this blog the textbook will be referred to as CM standing for Chemistry Matters.
Watch the following video clip