Qualitative analysis

Question 1

Potassium paper green equation

Answer 1

K2Cr2O7 + SO3 ——> Cr2(SO4)3

Question 2

Sodium nitroprusside test is used for

Answer 2

suphide ion
(violet coloration observed)
Na2S + Na2[Fe(CN)5NO] ——–> Na4[Fe(CN)5NOS]

Question 3

sodium nitroprusside formula

Answer 3

Na2[Fe(CN)5NO]

Question 4

Chromyl chloride test eq

Answer 4

K2Cr2O7 + H2SO4 + Cl- ——> CrO2Cl2 + K2SO4 + H2O
NaOH + CrO2Cl2 —–> Na2CrO4+ NaCl + H2O
Na2CrO4 + (CH3COO)2Pb ——> PbCrO4

Question 5

Grp1

Answer 5

Pb2+, Hg+, Ag+

Add HCl, we see a ppt

Question 6

Grp2

Answer 6

Cu2+, As3+

Add HCl, H2S we see a ppt

Question 7

Grp3

Answer 7

Fe3+, Al3+

NH4OH + NH4Cl + conc.HNO3

Question 8

Grp 4

Answer 8

Co, Mn,Ni,Zn

ppt

Question 9

Grp 5

Answer 9

Ba2+, Sr2+, Ca2+

Question 10

Grp 6

Answer 10

Mg2+

NH4OH + Na2HPO4

Question 11

chocolate brown ppt is test for

Answer 11

Cu2+

Cu2+ + K4[Fe(CN)6] ———> Cu2[Fe(CN)6] + K+

Question 12

Prussian blue test

Answer 12

Fe3+ + K4[Fe(CN)6] ———-> Fe4[Fe(CN)6]3

Question 13

blood red

Answer 13

CH3COO- + FeCl3 ——> Fe(CH3COO)3

(blood red)

Question 14

Lassaigne’s test is used for

Answer 14

halogens, S,P,N

Question 15

Leibeigs method is for

Answer 15

C and H

Question 16

Duma’s method is for

Answer 16

Nitrogen

Question 17

Kjeldahl’s method is used for

Answer 17

N

Question 18

Carius method is for

Answer 18

Cl, Br, I, S, P