Slides in this set
Why it is important for
substances to be identified
· It is vital for us to know what some substances
contain if the substance is for consumption,
for example checking drinking water samples
for impurities, so that it is not harmful for the
people who consume it.
· It is also important for substances to be
identified so we know what it can be used for.
· It is important to know how pure a substance
is if it is to be sold, so you can determine its
value. For example, pure gold is more valuable
than gold with impurities in it.…read more
Qualitative and Quantitative
· Qualitative analysis is the analysis of
what is in a substance.
· Quantitative analysis is the analysis of
how much of something is in a substance
eg. Finding out the concentration of an
· Ionic substances are identified by doing
tests to find the ions they contain.
· For example, sodium chloride (NaCl)
would be identified by doing a test for
the sodium ion (Na+) and the chloride ion
· The test for each ion must be unique
because if you did a test which applied to
all ions, then you could end up with one
result accounting for a more than one
Process for carrying out a flame
· Dip a wire loop in hydrochloric acid to
remove any residue on it that might
affect the result.
· Dip the wire loop in a sample of the salt
you want to test.
· Hold the loop in the bunsen flame and
observe the colour of the flame.…read more