Semi Micro Flashcards
Brisk Effervescence + Milky Baryta water and Lime water
Carbonate Present
Colorless gas (SO2) with the smell of burning sulfur. The gas turns a filter paper dipped in acidified potassium dichromate green.
Sulfite Present
Colorless gas with the odor of rotten eggs (H2S) is evolved. The gas
turns lead acetate paper black and cadmium acetate paper yellow.
Sulfide Present
Vinegar smell. Red coloration with neutral ferric chloride.
OR
Mix 20 mg of the substance with 1ml of ethyl alcohol and 5 drops of con.
H2SO4, Heat in a hot water rack for 10 minutes, and pour into 2 ml of Na2CO3
solution. Fruity odor.
Acetate Present
Greenish Yellow pungent smelling gas is evolved (HCl) White fumes when ammonia is presented on a glass rod.
Chloride Present
Reddish Brown Fumes are evolved (Br2).
Bromide Present
Violet Vapors (I2) are evolved.
Iodide present
On warming, brown gas (NO2)With characteristic smell is evolved. The brown color is deepened by the addition of
copper turnings.
Nitrate Present
Dil. Acid Group Rxn
To about 5 mg of the substance add about 0.5 ml of dil. HCl. Observe the
reaction in the cold and then heat it on a water bath.
Conc. Acid Group Rxn
Addition of Conc. H2SO4 + MnO2 with
heat
Brown ring test
The sodium carbonate extract is acidified with dil. H2SO4.
An equal volume of freshly prepared FeSO4 solution is added.
Holding the test-tube in an inclined position con. H2SO4 drops are added
without shaking.
A brown ring is formed at
the junction of the two
layers, Nitrate is confirmed.
Sulfate : BaCl2 test
To the sodium carbonate extract add dil. HCl till no more CO2 is evolved. Add 1-2 ml of dil. HCl and BaCl2 solution.
A white precipitate insoluble in dil. HCl is formed
Sulfate is confirmed.
Borate: Flame Test
The substance is mixed with calcium fluoride and con. H2SO4 to get a paste. Hold some of the paste on a platinum loop, just outside the base of the Bunsen flame.
A green flame is formed
Borate is confirmed.
Test for Bromide and Iodide:
To the substance in dil. HNO3 add drops of KMnO4 solution until the pink color persists. Add CCl4 and shake.
Reddish Brown Coloration: Bromide
Violet Coloration: Iodide
Silver nitrate group rxn
Add silver nitrate to Neutralized sodium carbonate extract.
