A species’ unique
chemical finger print provides the ability to determine the existence of a
particular species in an unknown sample. And based on its unique chemical
finger print, a separation scheme can be designed to separate and identify the
unknowns from an unknown mixture. Different separation schemes must be included
to prevent the failure of one particular scheme. If one or two procedures did
not go well/the expected result did not come out from one scheme, the other
scheme can be used to identify the rest of the cations.
Techniques of centrifuging
and decanting were used in this lab. A centrifuge is a laboratory device that
is used for the separation of liquids, gas and solids based on densities. The
laboratory centrifuge is driven by a motor and spins the liquid samples at high
speed. Decanting is the pouring of a liquid from one container to another
without disturbing the sediment. Hence the precipitates can be separated from
the aqueous mixture.
A separation scheme is
used instead of using flame tests and inductively coupled plasma optical
emission spectrometry. This is because carrying out the flame tests can be
dangerous and the color observed by the naked eye can be inaccurate. Also,
using the inductively coupled plasma optical emission spectrometry machines to
identify the cations are unrealistic as the machines are very expensive.