Chemistry - Chromatography - activity 4
Chromatography - activity 4
A chemist analysing a mixture of five alcohols uses gas chromatography to
determine if ethanol is present in the mixture.
Shown below is a representation of a chromatogram for a sample of a
mixture of five alcohols separated by gas chromatography -_ DIAGRAM 1_.
Also shown is a representation of a chromatogram for a slightly modified
mixture of the same five alcohols - _DIAGRAM 2_.
On studying the two chromatograms, the chemist decided that peak was
caused by ethanol.
(a) What was the slight modication made to the mixture of five alcohols
prior to obtaining the second chromatogram?
(b) How did a comparison of the first and second chromatograms enable the
chemist to deduce that peak was caused by ethanol?
(c) The alcohol with the lowest relative molecular mass was methanol CH3OH
and the alcohol with the highest relative molecular mass was 1-pentanol,
CH3(CH2)4OH. Suggest a label for the horizontal axis on the chromatograms
and identify which peaks were caused by these two alcohols.
* The general plan for analysis using a modern analytical instrument may
be represented as:
Previous | Next