experiment16

Pb2+, Cu2+ , Bi3+, Cd2+

Group II

Co2+, Ni2+, Fe3+, Cr3+, Mn2+, Zn2+

Group III

Ba2+, Sr2+, Ca2+

Group IV

Li+, Na+, K+

Group V

pH = 0.5, H2S (thioacetamide), Δ

PbS, CuS, Bi2S3, CdS

black ppt brown-orange or yellow ppt

Group III, IV, V

So yellow or white ppt (Discard)

Pb2+, Bi3+, Cd2+, Cu2+ light blue

white ppt

yellow ppt

Bi3+, Cd2+, Cu2+

white ppt

Bio

black ppt

Cu(NH3)42+, Cd(NH3)42+

dark blue colorless

maroon ppt

Cuo

black ppt H2S (thioacetamide), Δ

brown-orange or yellow ppt

pH = basic, H2S (thioacetamide), Δ

CoS, NiS, FeS, Cr(OH)3, MnS, ZnS

black gray-green pink white ppt

0.5 M HCl

CoS, NiS

black ppt conc. HNO3, HCl

So yellow or white ppt

(Discard) Co2+, Ni2+

dimethylglyoxime (DMG)

red ppt

HCl (till acidic) KSCN

isoamyl alc.-ether

blue or blue-green in alcohol-ether (upper) layer

Fe2+, Mn2+, Cr3+, Zn2+

Fe3+, Mn2+, Cr3+, Zn2+

NaOH, Na2O2

MnO2, Mn(OH)3, Fe(OH)3 black brown red-brown ppt

HNO3, NaNO2

Discard (if ppt remains) Mn

2+, Fe3+

purple soln

FeSCN2+

NaBiO3 HNO3

blood red soln

CrO42-, Zn(OH)42-

colorlessyellow

HCl (till acidic) ethylenediamine

K4Fe(CN)6

white ppt

HC2H3O2 Pb(C2H3O2)2

yellow ppt

Group IV, V

Cation Schematic

Original Soln Flame Test

Na+, Li+, K+

orange yellow

cobalt glasses used when Na+ is present

red light violet

NH4OH, (NH4)2CO3

Group V (Discard)

BaCO3, SrCO3, CaCO3

white ppt HC2H3O2, NH4C2H3O2, K2CrO4

yellow ppt Sr2+, Ca2+, (CrO42-)

white ppt

flame test

yellow-green

NH4OH, ethyl alcohol

yellow ppt

flame test

red

white ppt

flame test

red-orange

basic (NH4OH)

HNO3

(NH4)2SO4

PbSO4

NH4C2H3O2

PbCrO4

NH4OH

Bi(OH)3

Na2SnO2

K4Fe(CN)6

Cu2Fe(CN)6

Na2S2O4

Cd2+

CdS

Co(SCN)42-

HNO3

MnO4-

KSCN

Zn2Fe(CN)6PbCrO4

K2CrO4

Pb(C2H3O2)2

BaCrO4

HCl

Ba2+

H2SO4

BaSO4

SrCrO4

HCl

Sr2+

Ca2+

∆, (NH4)2C2O4

CaC2O4

HCl

Ca2+

Ni(DMG)2

If alcohol-ether layer is red or purple, add NH4HF2,, until the red or purple disappears to

see if a blue-green color is present.

**

** NH4HF2