This Support Material booklet is designed to accompany the OCR Advanced GCE specification in Chemistry B (Salters) for teaching from September 2008.
Contents
Contents 2
Support Materials 3
Choice of investigation topic 4
Health and Safety 33
Other forms of support 35
Support Materials
These support materials should be read in conjunction with two other documents:
Practical Skills Handbook: available via OCR Interchange https://interchange.ocr.org.uk and at www.ocr.org.uk;
The Specification, OCR Advanced GCE in Chemistry B (Salters): H435: available …show more content…
13
The Freundlich adsorption isothem
Shake different concentrations of ethanoic acid with activated charcoal, filter and find the concentration of acid remaining in solution by titration with sodium hydroxide solution. Use data to calculate the Freundlich constants
Extend to other acids such as methanoic, propanoic, ethanedioic acids
Starter page
Internet sources
Project more suitable for students with a mathematical background
14
The amount of copper in brass
Compare different methods for finding the concentration of copper(II) ions in solution. Could include redox titration, colorimetry, ion exchange followed by acid/base titration, gravimetric, use of an electrochemical cell.
Starter page
Chemistry Review Project page ‘The concentration of copper …show more content…
Then you titrate the iodine remaining with sodium thiosulfate solution using starch indicator. Because you know how much iodine was produced from iodate(V) and iodide and you have found by titration how much is left over you can calculate how much iodine must have reacted with the ascorbic acid.
First you will need to analyse a solution of ascorbic acid with a known composition. By doing this you will be able to tell how accurate your experiments are.
Pipette 25.0 cm3 of an ascorbic acid solution containing 1.0 g dm–3 into a conical flask. Add 25.0 cm3 of potassium iodate(V) solution, 5.0 cm3 potassium iodide solution and 5.0 cm3 sulfuric acid. Titrate the iodine remaining with the sodium thiosulfate solution using starch indicator.
Are the amounts of materials that you used appropriate or do you need to modify them in order to get an appropriate titre?
When you are satisfied that you have appropriate amounts you can carry out sufficient accurate titrations that will enable you to calculate the amount of vitamin C in your solution and to compare with the known