Chemistry Experiments: Flame Test, Sulphate Test, Carbonate Test, Nitrate Test, Halide Test, Chromatography, Chemical Identification

Solution
Task 1
i. Flame test
Procedure
 Dip a platinum or nichrome wire in a concentrated hydrochloric acid and then
hold it into a hot Bunsen flame
 When the nichrome wire is clean up, then dip it into the amount of solid you are
testing
 Place the wire back to the flame again
Observation and presence of ions
Flame colour Metals presences in the solution
Red Lithium
Strong persisted orange Sodium
Lilac Potassium
Reddish-violet Rubidium
Blue – violet Caesium
Orange –red Calcium
Blue-green Copper
Greyish- white Lead
Pale-green Barium
ii. Sulphate test and sulphite
Procedure
 To 2.0 cm3 of sodium sulphate in a test tube, add 2.0 cm3 of barium chloride or
nitrate solution
 To the mixture add 2 cm3 of dilute hydrochloric acid or dilute nitric (V) acid
 Repeat the above two procedure using a solution of sodium sulphite
Observation and conclusion
A white precipitate, insoluble in the dilute acid was observed, this indicate the
presence of sulphate ions
A white precipitate which dissolves in dilute acid with production of a colourless
gas which turns filter paper soaked in acidified orange potassium chromate (VI)
from orange to green indicate the presence of sulphite ions

iii. Carbonate test
Procedure
 Place a spatulaful of sodium carbonate in a clean test tube
 Add 2 cm3 of hydrochloric acid
 Add 2 cm3 of lime water
 Place a burning split at the open end of the test-tube
Observation and conclusion
Carbonates react with hydrochloric acid evolving carbon dioxide gas that forms a
white precipitate with lime water.
The gas also extinguishes a burning wooden split
iv. Nitrate test
Procedure
 Place one spatulaful of sodium nitrate into a clean test tube
 Add 2 cm3 of distilled water and shake the mixture
 Add 1 cm3 of freshly prepared iron (II) sulphate and shake
 Add concentrated sulphuric acid slowly and carefully along the wall of the test
tube
Observation
When concentrated sulphuric acid is added to the mixture of sodium nitrate and
iron (II) sulphate solution, the aciod sinks to the bottom, this because the acid is
denser than the solution.
The reaction produces heat
A brown ring is due to the formation of iron (II) sulphate-nitrogen (II) oxide
complex ( FeSO4 .NO)
Conclusion
All nitrates gives the same result and the reaction is reffered to as the brown ring
test for nitrates
v. Halide test
Apparatus
Test-tubes rack, test-tube, solutions that will be used for testing that include KCl, KBr
and KI, together with acidified silver nitrate solution reagent and dilute ammonia
solution.

Procedure
 Put 2 cm3 of KCl solution into a test tube.
 Add 2 cm3 of silver nitrate solution.
 Note the observation and record all the changes that will take place in the test tube.
 Put 2 cm3 of KBr solution into another clean test tube and repeat procedure (ii) and (ii).
 Put 2 cm3 of KI solution into a clean third test tube and repeat procedure (ii) and (iii).
Observation
Table 1 Precipitates obtained with silver nitrate solution
Ions Observation
chloride Presence of white precipitate
bromide Presence of cream precipitate
iodide Presence of pale yellow precipitate
Task 2