I have recently had to test 6 unknown compounds to identify their functional group. I need to know why alchols and aldehydes would decolourise bromine water? I thought it would identify the Alkenes without any false tests can anyone shed any light, apparently it may be to do with haloalkanes???
2007-03-26 12:07:22 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry
bromine is an oxidizing agent, and so a number of different groups can be oxidized by bromine. Alcohols can be oxidized to aldehydes or to carboxyl groups, and carbonyl's can, as well. I'm not certain of the absolute strength of bromine as an oxidizing agent, but it seems reasonable that that is what happened in your tests.
2007-03-26 12:16:15 · answer #1 · answered by hcbiochem 7 · 1⤊ 0⤋
Alcohols shouldn't have decolorized the bromine water, though the aldehydes definitely would. The aldehydes react because of keto-enol tautomerization...even though the equilibrium may favor the aldehyde, there is some of the highly reactive enol always present in solution and it reacts immediately, thus driving the equilibrium to the left with time.
Unless your alcohols were tertiary, or has some local R group able to stabilize forming a carbocation, they shouldn't have reacted.
2007-03-26 20:21:38 · answer #2 · answered by Anonymous · 0⤊ 0⤋
the compounds that turned bromine water colourless, are unsaturated.
2007-03-28 20:59:02 · answer #3 · answered by Acorn barnacle 2 · 0⤊ 1⤋