Confirmatory tests (anions)

Question 1

carbonate

Answer 1

dil hcl test
Os+ dil hcl
brisk effervescence and evolution of colourless, odourless gas , turns lime water milky
mgso4 test
Os+mgso4 soln
formation of white ppt in the cold

Question 2

sulphide (S2-)

Answer 2

sodium nitroprusside test
OS+ few drops of sodium nitroprusside soln
purple or violet color obtained
Lead acetate test
OS+ lead acetate soln
black ppt

Question 3

Cl-

Answer 3

silver nitrate test
OS+ dil hno3 +boil+cool+ add silver nitrate soln
a curdy white ppt which is solubile in nh4oh
Chromyl chloride test
salt+ powdered potassium dichromate+ conc h2so4+ heat+ pass the red vapors in naoh soln+
yellow soln obtained
yellow soln+ dil acetic acid+ lead acetate soln
yellow ppt formed

Question 4

br-

Answer 4

silver nitrate test
OS+ dil hno3+ boil + cool+ silver nitrate soln
light yellow ppt (partially soluble in nh4oh)
chlorine water test
OS+ dil hcl+ 1-2 ml of carbon disulphide+ chlorine water+ shake+ allow to stand
carbon disulphide layer acquires orange colouration

Question 5

No3- (Nitrate)

Answer 5

copper chips test
heat salt with conc h2so4+ add few copper chips
dark brown fume sof no2 are evolved
ring test
OS+ ferrous sulphate soln +Conc h2so4 slowly along the sides of the tube
dark brown ring is formed at the junction of the layers of the acid and soln

Question 6

acetate (Ch3coo-)

Answer 6

oxalic acid
take salt on watch glass, mix with solid oxalic acid, prepare paste of it by adding water, rub and smell
smells like vinegar
fecl3 test
Os +neutral fecl3+ divide in two parts
(i) add dil hcl
reddish color disappears
(ii) add water and boil
reddish brown ppt

Question 7

oxalate (c2o42-)

Answer 7

cacl3 test
OS+ dil acetic acid + boil off co2+ add cacl3 soln
white ppt formed
white ppt+ dil hno3+ warm
ppt dissolves
potassium permanganate test
salt+ dil h2so4+ warm+ 1-2 drops of dil soln of kmno4
pink colour decolourises and co2 is evolved

Question 7

SO42- (sulphate)

Answer 7

bacl2 test
OS+ bacl2 soln
white ppt formed which is insoluble in dil hcl
lead acetate test
OS+ lead acetate soln
white ppt which is soluble in excess hot ammonium acetate soln

Question 7

SO42- (sulphate)

Answer 7

bacl2 test
OS+ bacl2 soln
white ppt formed which is insoluble in dil hcl
lead acetate test
OS+ lead acetate soln
white ppt which is soluble in excess hot ammonium acetate soln

Question 8

phosphate (PO43-)

Answer 8

ammonium molybdate test
OS+ conc hno3+ boil+ ammonium molybdate soln in excess+ boil
deep yellow ppt or colouration is obtained
magnesia mixture test
OS+ dil magnesia mixture+ allow to stand
white ppt obtained