Applied Science BTEC Nationals/Chemical Laboratory Techniques

Prepare, isolate and purify compounds.

One inorganic compound

One organic compound

One substance extracted from a natural or synthetic material

Procedures.

Safe dispensing of chemicals.

Avoidance of contamination of reagents.

Mixing chemicals safely.

Heating and boiling under reflux.

Control and monitoring of reactions.

Safe disposal of substances.

Isolation and purification.

Solvent extraction

Evaporation

Filtration (gravity and reduced pressure)

Distillation (simple and fractional)

Paper and thin layer chromatography

Analyse compounds.

Qualitative analysis of inorganic substances: tests for anions and cations.

Qualitative analysis of organic substances: tests for functional groups; identification of aldehydes and ketones from melting points of derivatives.

Quantitative analysis — volumetric: preparation of standard solutions; titrations.

Qualitative analysis: use of pH meter; use of colorimeter.

Calculate percentage yield and percentage purity.

Yield: theoretical yield; actual yield; percentage yield

Percentage purity: calculate % purity w/w

Experiments

Measuring the iron content of iron tablets.

Extracting plasticisers from PVC.

Extracting caffeine from tea.

Synthesis of ethanal by oxidation.

Synthesis of benzoic acid by oxidation.

Synthesis of aspirin by esterification.

Synthesis of ethyl ethanoate by esterification.

Preparation of Kastle-Meyer test reagent.

Extraction and presumptive testing of cocaine.

Synthesis and analysis of iron (II) ethanedioate.

Resources

Edexcel recommend the following resources.

Textbooks

Clark J — Calculations in AS/A Level Chemistry (Longman, 2000) ISBN 0582411270

Faust C B — Modern Chemical Techniques (The Royal Society of Chemistry, 1905) ISBN 1870343190

Hill G and Holman J — Chemistry in Context (Nelson Thornes, 2004) ISBN 0174481918

Hill G and Holman J — Chemistry in Context: Laboratory Manual and Student Guide (Nelson Thornes, 2001) ISBN 0174483074

Hunt A — Advanced Level Practical Work for Chemistry (Hodder Murray, 2004) ISBN 0340886722

Levinson R — More Modern Chemical Techniques (The Royal Society of Chemistry, 2001) ISBN 0854049290

MacDonald K — Getting the Message Across: Key Skills for Scientists, 3rd Edition (The Royal Society of Chemistry, 2001) ISSN 14717166 page 12

Ramsden E N — Calculations for A-Level Chemistry (Nelson Thornes, 2001) ISBN 0748758399

Websites

Royal Society of Chemistry — aspirin activities.

How to read Material Safety Data Sheets — University of Bristol — site also contains links to major manufacturers’ information.

Chemical Industries Association.

Creative Chemistry website (A-level practical work).

Physical Sciences Educational Reviews.

Royal Society of Chemistry.

Practical techniques.

Chemical Industry Education Centre.