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
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(d) explain the need to use locating agents in the chromatography of colourless compounds
CM - Chapter 3 p39
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(e) deduce from the given melting point and boiling point the identities of substances and their purity
CM - Chapter 3 p32-35
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(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
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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

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(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
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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