18:25 ll 15
You are given an unknown Substance and
told that it could be one of the three substances.
L. Mor N. You developed the two sets of
chromatograms below. From the chromatograms,
deduce the identity of X
台
solvent -
front
starting -
line
XLMN
developed
with water
XL M N
developed
with ethanol
A It could be either Lor M.
B It could be either Mor N.
C It must be La
DIt must be N.
Problem-solving strategy:
If two substances are identical, they will
have the same height on a chromatogram
regardless of the solvent used.
3. Dyes that are allowed in loods are given E
numbers. Four such E numbers commonly
used in soups are E120, E122, E124 and E162.
The chromatogram below was obtained from
three tomato soups X, Y and Z. Soup 2 was a
new soup on the market. A chemist was testing
it to ensure that all of the dyes used in making
the soup were legal.
Х
Y
Z
E120 122 E124 E162
a) Explain wity water can be used as a solvent.
b) Why was the pencil line, on which the spots
were placed, drawn above the level of the
solvent?
c) Which soup contains all lour E numbers?
d) Are the E numbers in soup 2 legp? Explain
your awer.
IM​