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A

2mL test solution +

8 drops 6M HCl

(avoid excess)

If no ppt forms proceed to B

Decantate

Centrifuge

B

Precipitate

(Group I Cations:

Insoluble clorides)

Adjust pH to 0.5

by adding 6M

NaOH/HCl

Decantate

+ 2mL boiled H2O

centrifuge and decant

immediately (repeat)

+ add 2 drops of 1M

K2CrO4

Precipitate

+ 5 drops 6M NH3 (stir

to break ppt) then

centrifuge and decant

(repeat)

Precipitate

(discard)

+ 2mL 5%

thioacetamide

and stir

If ppt forms warm in

water bath and dissolve

Heat in boiling

water bath (10

mins)

No ppt? Proceed

to part C.

Yellow ppt  Pb 2+

Acidify

with 6M

HNO3

(litmus

paper)

Decantate

Precipitate (black)

Group II Cations:

Insoluble Sulfides

White ppt

 Ag +

Cool, centrifuge &

decant

Precipitate

Decantate

pH 0.5 by adding

dropwise 0.5 M

NaOAc/HOAc

Stir after drop

Precipitate

+ 2 mL 1M NH4Cl + 2 mL

H2O stir, centrifuge

+ 15 drops 6M

HNO3 heat in

bath(few mins) &

centrifuge

Decantate (discard)

Precipitate

Decantate

Precipitate

+ 1 mL water centrifuge,

discard decantate

Decantate

Precipitate

(discard):

Elemental S

+ 2-3 drops 6M HCl,

centrifuge, decant (white ppt

means there’s lead)

Precipitate

+ 10 drops 1M NaOAc,

heat to dissolve ppt

+ 2 drops 1M K2CrO4

If colorless

+ 1 mL M NH4Cl + 1 mL

H2O stir, combine w/

+ 2mL, 5%

thioacetamide,

warm bath

Yellow ppt  Cd 2+

+6M NH3 basic to litmus

Decantate

C

Boiling bath (3mins),

cool, centrifuge, decant

If Blue, divide to 2

+ pinch Na2S2O4, warm bath,

centrifuge (discard ppt)

+pinch Na2S2O4,

warm bath,

centrifuge & discard

ppt

Yellow ppt  Pb2+

Group 3 Cations: Base

insoluble Sulfides & OH

+6M HOAc  Acidic

& colorfades

+ 1mL 5%

thioacetamide, warm

bath (5mins)

+1drop K4Fe(CN)6

+ 1mL 15M NH3 (stir

ppt), warm bath

(5mins), centrifuge

Red ppt  Cu2+

Decantate

Precipitate

Wash w/ few drps H2O...