Logged out
Access All our Essays in an Instant
Swap your work for FREE access, or pay £4.99 for instant access
Identify an unknown substance through a series of tests that should systematically eliminate all other possible substances.
Member rating:
(7 votes)
| Words:
| Submitted: Tue Nov 04 2003
Page Preview
On the left is an image preview of every page of this document, and below are the first 150 words with formatting removed:
A2 - Assessed Practical (Skill P) Introduction. Alcohols. 'Alcohols are a family of organic compounds in which the -OH functional group is attached to a hydrocarbon chain', pg. 296 Chemistry for Advanced level, Third edition. A substance can be tested for the presence of this functional group by selective oxidation. 'A solution of acidified potassium dichromate ions is often used as the oxidising agent. In the reaction the orange dichromate (VI) ions are reduced to green chromium (III) ions' pg 308, Chemistry for Advanced Level, Third Edition, Cr2O72 - + 14H+ + 6e- 2Cr3+ + 7H2O The overall equation is: 2Cr2O72 -(aq) + 3C2H5OH(l) + 16H+(aq) 4Cr3+(aq) + 3CH3CO2H(aq) + 11H2O(l) Ketones. Oxidation of secondary alcohols produces ketones, e.g. propanone and contains a C=O bond, where the carbon atom is also bonded to a CH3 group. 'The basic method of identification of an unknown carbonyl compound is to make a solid derivative and then measuring the melting...
To see the full version of this document, and 143,586 others
