Salt Analysis2

(1)

Salt Analysis

Step 1:

Step 1: Note Colour of SaltNote Colour of Salt C

Coolloouur r oof f SaSalltt IInnffeerreennccee B

Blluue e oor r BBlluuiissh h GrreG eeenn CCuu2+2+ _{or Ni}_{or Ni}2+2+

G Grreeeenn NNii2+2+ L Liigghhtt GGrreeeenn FFee2+2+ L Liigghhtt PPiinnkk MMnn2+2+ D Daarrkk BBrroowwnn FFee3+3+ Y

Yeellllooww FFee3+3+ _{or ferrous carbonate}_{or ferrous carbonate}

W

Whhiittee AAlll l aabboovve e mmeennttiioonneed d ccaattiioonns s aarree absent

absent

Step 2:

Step 2: Smell the salt. Rub a little of the given salt between your fingers andSmell the salt. Rub a little of the given salt between your fingers and smell.

smell. S

Smmeellll IInnffeerreennccee

S

Smmeelll l oof f vviinneeggaarr CCHH33COOCOO

--A

Ammmmoonniiaaccaal l SmSmeellll NNHH44++

S

Smmeelll l lliikke e rrootttteen n eeggggss SS

--Step 3:

Step 3: Flame test. Make a paste of salt with concentrated HCl andFlame test. Make a paste of salt with concentrated HCl and introduce small quantity into oxidising flame.

introduce small quantity into oxidising flame. C

Coolloouur r oof f FFllaammee IInnffeerreennccee B

Brriicckk rreedd CCaa2+2+

C

Crriimmssoonn rreedd SSrr2+2+

Lig

Light ht GrGreen een (ap(appeapears rs aftafter er somsometietime)me) BaBa2+2+

B

Blluuiisshh GGrreeeenn CCuu2+2+

Step 4:

Step 4: Solubility test.Solubility test. Original Solution Original Solution Cold distilled water Cold distilled water Hot distilled water Hot distilled water Cold dilute HCl Cold dilute HCl Hot dilute HCl Hot dilute HCl Cold concentrated HCl Cold concentrated HCl Hot concentrated HCl Hot concentrated HCl

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Step 5 (If salt doesn’t

Step 5 (If salt doesn’t dissolve in distilled water):dissolve in distilled water): Make sodiumMake sodium extract (S.E).

extract (S.E).

Steps to prepare sodium extract: Steps to prepare sodium extract:

1.

1. Add 1 pAdd 1 portortion oion of salt tf salt to beao beakerker..

2.

2. Add 3 portions of NaAdd 3 portions of Na22COCO33..

3.

3. Add Add 1010-15 -15 ml ml of wof wateaterr 4.

4. BoiBoil the mil the mixtuxture fore for 5 minr 5 minuteutess 5.

5. CoCool tol the mhe mixixtuturere..

6.

6. Filter the mixture.Filter the mixture. 7.

7. Use Use resiresidue due for for the the expeexperimeriment.nt. Step 6:

Step 6: Test for ammonia. Test for ammonia. T

Teesst t ffoor r AAmmmmoonniiaa IInnffeerreennccee Boil the O.S and pass effervescence

Boil the O.S and pass effervescence through nessler’s reagent.

through nessler’s reagent.

Nessler’s reagent turns orange. Nessler’s reagent turns orange. Heat a small quantity of salt with

Heat a small quantity of salt with NaOH solution.

NaOH solution.

Ammoniacal smell. Ammoniacal smell.

Step 7:

Step 7: Dilute HDilute H22SOSO44 test for anions. Add salt to dilute Htest for anions. Add salt to dilute H22SOSO44and heat andand heat and

pass effervescence through pass effervescence through L

Liimme e WWaatteerr LLiimme e wwaatteer r ttuurrnns s mmiillkkyy CCOO332-

2-Lead acetate paper (gas Lead acetate paper (gas evolved smells of rotten evolved smells of rotten eggs)

eggs)

Lead Acetate paper Lead Acetate paper turns black turns black S S2- 2-Acidified Potassium Acidified Potassium dichromate paper dichromate paper Potassium dichromate Potassium dichromate paper turns green paper turns green

SO SO332-

2-FeSO

FeSO44 ssoolluuttiioonn FFeeSSOO44 solution turnssolution turns

black black

NO NO22

--A

Anniioonn CCoonnffiirrmmaattoorry y TTeesstt RReessuulltt CO

CO332-2- Shake salt with waterShake salt with water

and filter. and filter. (Soluble CO

(Soluble CO332-2-)) •• Filtrate + dil. HClFiltrate + dil. HCl •

• Filtrate + MgSOFiltrate + MgSO₄₄

•

• COCO₂₂ withwith

effervescence effervescence

•

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(Insoluble CO

(Insoluble CO332-2-)) RReessiidduue e + + ddiill. . HHCCll CCOO22 with effervescence.with effervescence.

S

S2-2- _{W.E or S.E + acetic acid}_{W.E or S.E + acetic acid}

(3 drops) + Lead (3 drops) + Lead acetate solution acetate solution Black precipitate Black precipitate SO

SO332-2- W.E or S.E + BaClW.E or S.E + BaCl22

solution solution

White precipitate White precipitate

formed which dissolves formed which dissolves in excess in dil. HCl in excess in dil. HCl NO

NO22-- W.E + acetic acid (2W.E + acetic acid (2

drops) + FeSO drops) + FeSO44

Dark red colour Dark red colour

Step 8:

Step 8: Concentrated HConcentrated H22SOSO44test for anions. Add salt to concentrated Htest for anions. Add salt to concentrated H22SOSO44

and pass effervescence through and pass effervescence through AgNO

AgNO33 ssoolluuttiioonn WWhhiitte e pprreecciippiittaattee

formed in AgNO formed in AgNO33 solution solution Cl Cl --S

Sttaarrcch h ppaappeerr SSttaarrcch h ppaappeer r ttuurrnnss yellow or orange yellow or orange

Br Br

--S

Sttararcch h ppapapeer r ttuurrnns s bblluuee II

--FeSO

FeSO44 ssoolluuttiioonn FFeeSSOO44 solution turnssolution turns

black black

NO NO33

--If none of the above tests are positive test for SO

If none of the above tests are positive test for SO442-2- and acetateand acetate

A

Anniioonn CCoonnffiirrmmaattoorry y TTeesstt RReessuulltt Cl

Cl-- _{S.E + dil. HNO}_{S.E + dil. HNO}

3

3. Boil and. Boil and

add AgNO

add AgNO33solution.solution.

White precipitate White precipitate soluble in NH soluble in NH44OH.OH.

Br

Br-- _{S.E + dil. HNO}_{S.E + dil. HNO}

3

add AgNO

Pale yellow precipitate Pale yellow precipitate which is partially soluble which is partially soluble in NH

in NH44OH.OH.

II-- _{S.E + dil. HNO}_{S.E + dil. HNO}

3

add AgNO

Yellow precipitate Yellow precipitate

insoluble in NH insoluble in NH44OH.OH.

NO

NO33-- Salt + conc. HSalt + conc. H22SOSO44 +Cu+Cu

chips. Heat. chips. Heat.

Reddish brown vapours. Reddish brown vapours. W.E + FeSO

W.E + FeSO44 + conc.+ conc.

H

H22SOSO44by sides of testby sides of test

tube. tube.

Brown ring formed. Brown ring formed.

CH

CH33COOCOO-- W.E + neutral FeClW.E + neutral FeCl33

solution solution

Blood red colour. Blood red colour. SO

SO442-2- W.E or S.E + dil. HCl +W.E or S.E + dil. HCl +

BaCl

BaCl22 solutionsolution

White precipitate White precipitate formed which is formed which is insoluble in dil. HCl insoluble in dil. HCl

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Step 9:

Step 9: Test for Cations. (Check confirmation table if a group precipitates) Test for Cations. (Check confirmation table if a group precipitates) E

Exxppeerriimmeenntt OObbsseerrvvaattiioonn IInnffeerreennccee Group 1:

Group 1: To O.S add To O.S add dilute HCl.

dilute HCl.

White precipitate if White precipitate if formed

formed

Pb

Pb2+2+_{, Ag}_{, Ag}++

Group 2:

Group 2: Acidify O.SAcidify O.S with dilute HCl and pass with dilute HCl and pass H

H22S gas through it.S gas through it.

Black precipitate is Black precipitate is formed formed Pb Pb2+2+_{, Cu}_{, Cu}2+2+ Group 3:

Group 3: Boil of HBoil of H22SS

gas completely and gas completely and then add I gm of NH then add I gm of NH44ClCl

and 0.5 cm

and 0.5 cm33 _{of conc.}_{of conc.}

HNO

HNO33. Boil and cool and. Boil and cool and

then add NH

then add NH44OH till itOH till it

smells of ammonia. smells of ammonia.

•

• Reddish brownReddish brown

precipitate precipitate

•

• White precipitateWhite precipitate •

• Green precipitateGreen precipitate

•

• For FeFor Fe2+2+: : O.S O.S oror

filtrate of group 2 + filtrate of group 2 + Potassium Potassium ferricyanide solution. ferricyanide solution. • • FeFe3+3+ • • AlAl3+3+ • • CrCr3+3+ • • FeFe2+2+ Group 4:

Group 4: Pass HPass H22S gasS gas

through solution of through solution of group 3

group 3 or

or

O.S + NH

O.S + NH44OH+ HOH+ H22S gasS gas

•

• White precipitateWhite precipitate •

• Black precipitateBlack precipitate •

• Flesh colouredFlesh coloured

precipitate precipitate • • ZnZn2+2+ • • NiNi2+2+ • • MnMn2+2+ Group 5:

Group 5: Take FiltrateTake Filtrate of group 4. Boil of H of group 4. Boil of H22SS

and divide solution into and divide solution into three parts. Add NH three parts. Add NH44Cl,Cl,

NH

NH44OH and (NHOH and (NH44))22COCO33..

Filter. Filter.

W

Whhiitte e pprreecciippiittaattee BBaa2+2+_{, Sr}_{, Sr}2+2+ _{or Ca}_{or Ca}2+2+

Group 6:

Group 6: To filtrate add To filtrate add a pinch of NH

a pinch of NH44OH andOH and

excess of ammonium excess of ammonium phosphate solution. phosphate solution.

W

Whhiitte e pprreecciippiittaattee MMgg2+2+

Confirmati

Confirmation on Table:Table: C

Caattiioonn CCoonnffiirrmmaattoorry y TTeesst t RReessuulltt Pb

Pb2+2+ _{Boil the white}_{Boil the white}

precipitate with distilled precipitate with distilled water and divide

water and divide

solution into two parts solution into two parts

•

• To one part add KI To one part add KI

solution solution

•

• To second part add To second part add

K

K 22CrOCrO44 solutionsolution

•

• Yellow precipitate Yellow precipitate •

• Yellow precipitate Yellow precipitate

Cu

Cu2+2+ _{Dissolve black}_{Dissolve black}

•

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precipitate in 50% precipitate in 50% HNO

HNO33. Bluish green. Bluish green

solution formed. solution formed.

•

• Add excess of NHAdd excess of NH44OHOH

solution to bluish solution to bluish green solution. green solution.

•

• Acidify bluish greenAcidify bluish green

solution with acetic solution with acetic acid and add

acid and add potassium potassium ferrocyanide ferrocyanide solution. solution. •

• Chocolate brownChocolate brown

precipitate. precipitate.

Fe

Fe3+3+ _{Dissolve brown}_{Dissolve brown}

precipitate

precipitate in in dilute dilute HClHCl and divide into two

and divide into two parts.

parts.

•

• To first part add To first part add

potassium potassium

ferrocyanide solution ferrocyanide solution

•

potassium potassium sulphocyanide sulphocyanide solution. solution. •

• Prussion blue colourPrussion blue colour

or precipitate or precipitate

•

• Blood redBlood red

colouration. colouration.

Fe

Fe2+2+ _{O.S + Potassium}_{O.S + Potassium}

ferricyanide solution ferricyanide solution A blue colour or A blue colour or precipitate precipitate Al

Al3+3+ _{White precipitate + dil.}_{White precipitate + dil.}

HCl + few drops of blue HCl + few drops of blue litmus solution + NH litmus solution + NH44OHOH solution in excess solution in excess A blue precipitate A blue precipitate suspended in a suspended in a colourless liquid colourless liquid Zn

Zn2+2+ _{Dissolve part of white}_{Dissolve part of white}

precipitate in dil. HCl. precipitate in dil. HCl. Divide solution into two Divide solution into two parts.

parts.

•

• To one part add To one part add

potassium potassium

ferrocyanide solution ferrocyanide solution

•

NaOH solution NaOH solution

•

• Bluish whiteBluish white

precipitate precipitate

•

• White precipitateWhite precipitate

soluble in excess of soluble in excess of NaOH

NaOH

Ca

Ca2+2+_{, Sr}_{, Sr}2+2+ _{and Ba}_{and Ba}2+2+ _{Dissolve white}_{Dissolve white}

precipitate

precipitate in in dil. dil. AceticAcetic acid. Boil of CO

acid. Boil of CO22..

•

• To one part K To one part K 22Cr0Cr044

solution. solution.

•

ammonium sulphate ammonium sulphate

•

• Yellow precipitate Yellow precipitate

confirms Ba confirms Ba2+2+_..

•

confirms Sr confirms Sr2+2+_..

•

confirms Ca confirms Ca2+2+_..

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solution. solution.

•

• To third part add To third part add

ammonium oxalate ammonium oxalate solution.

solution. Mg

Mg2+2+ _{Wash and suspend a}_{Wash and suspend a}

part of white precipitate part of white precipitate in water. Add a drop of in water. Add a drop of HCl followed by a few HCl followed by a few drops of magneson drops of magneson reagent and excess of reagent and excess of NaOH solution NaOH solution Blue precipitate or Blue precipitate or colouration. colouration.