Experiment QA1
Qualitative Analysis
Name:
Seat No.:
Date:
Grade:
Specimen results
1. Describe the sample.
2. Report on the solubility of the sample in
Blue powder.
Insoluble.
water.
3. Estimate, using universal test paper, the pH
pH = 7
of an aqueous solution of the sample.
4. Heat a small amount of the solid sample in
an ignition tube, at first gently and then
strongly.
Colourless gas evolved which turns lime water milky.
Colourless liquid condenses on cooler part of the
tube.
Report the observations.
5. Carry out a flame test and report the
Flame colour: Blue
observations.
6. Report on the action of 2 M H2SO4 on an
Gas evolved which turns lime water milky.
aqueous solution of the sample.
7. Report on the action of conc. H2SO4 on the
Gas evolved which turns lime water milky.
solid sample.
8. Report on the action of conc. HNO3 on the
Gas evolved which turns lime water milky.
solid sample.
9. Report on the action of 2 M NaOH on an
Pale blue gelatinous precipitate is formed.
aqueous solution of the sample.
10.Report on the action of dilute aqueous
NH3 on an aqueous solution of the sample.
Pale blue precipitate is formed.
Precipitate dissolves in excess NH3(aq) to form a deep
blue solution.
11.Report on the action of a few drops of 0.2
M KMnO4 in 2 M H2SO4 on an aqueous
No visible change.
solution of the sample.
12.Report on the action of zinc and 2 M
H2SO4 on an aqueous solution of the
Gas evolved which turns lime water milky.
sample.
P.1
From the result of the above tests, deduce which cation(s) and anion(s) may be present in the
solid sample.
The sample is a blue powder which is insoluble in water, it is neutral, its flame colour is
blue (inference: Cu2+), when the sample is heated strongly, a colourless gas is evolved which
turns lime water milky (inference: CO32-, HCO3-), and a colourless liquid condenses on the
cooler part of the ignition tube (inference: H2O). An aqueous solution of the sample reacts
with dil. and conc. acid with evolution of a colourless gas which turns line water milky
(inference: CO32-, HCO3-). When an aqueous solution of the sample is treated with dil.
NaOH, a pale blue gelatinous precipitate is formed. When treated with NH3(aq), a pale blue
gelatinous precipitate is formed first and the precipitate dissolves in excess NH3(aq) to form
a deep blue solution (inference: Cu2+).
Therefore, the sample is a hydrated salt, it may contains Cu2+ ions and CO32- ions.
P.2