CHEMISTRY LAB MANUAL · 2020-03-23 · Benzaldehyde,acetone,solid NaOH and ethanol. Theory : Dibenzalacetone [ 1,4-pentadien-3-one, 1,5-diphenyl-] is prepared by condensation of acetone

THE CAMFORD INTERNATIONAL

SCHOOL

CLASS:XII

SESSION:2020-21

CHEMISTRY

LAB MANUAL

PREPARATION OF INORGANIC COMPOUNDS.

EXPT: NO: 1

PREPARATION OF DOUBLE SALT – FERROUS

AMMONIUMSULPHATE.

Aim:To Preparation of a Double Salt – Ferrous Ammonium Sulphate.

Material Required:

Beakers, China Dish,Funnel,GlassRod,Tripod stand, Wire

Gauze,Burner,Washbottle,Measuring jar, and Electronic balance.

Chemical Required:

Ferrous sulphate, Ammonium sulphate, Dil. Sulphuric acid, Ethyl

alcohol and Distilled water.

Theory :

When an equimolar solution of hydrated ferrous sulphate and

ammonium sulphate in are mixed with water containing a few mL

of dil. H2SO4 is added to prevent the hydrolysis of FeSO4.7H2O

then subjecting the resulting solution to the crystallization

point.Cooling of the hot saturated solution yields light green

crystals of Mohr’s salt.

FeSO4.7H2O + (NH4)2 SO4 → FeSO4.(NH4)2SO4.6H2O +H2O

Procedure:

1. Take 7g ferrous sulphate 3.5g ammonium sulphate in a clean

250mL beaker.

2. To this add about 2-3mL of dil.sulphuric acid to prevent the

hydrolysis of ferrous sulphate.

3. In another beaker, boil about 20mL of water for 5 minutes.

4. Add the boiling hot water to the contents of the first beaker in

small quantities at a time.

5. Stir the contents of the beaker with a glass rod until the salts

have completely dissolved.

6. Filter the solution to remove undissolved impurities and transfer

the filtrate into a china dish.

7. Now heat the solution in the china dish until its crystallization

point is reached. Then transfer the solution into a crystallizing

dish and keep it undisturbed.

8. On cooling, crystals of Mohr’s salt separate.

9. Decant the mother liquor and dry the crystals.

Precautions:

1. Cool the solution slowly to get good crystals.

2. Never disturb the solution during crystallization,it should be

covered with a watch glass.

3. Do not heat the solution for a long time as it may oxidize

ferrous ions to ferric ions.

Observation :

1. Weight of crystals obtained=

2. Colour of the crystals = ....

3. The shape of the crystals = ....

RESULT:

-------------------------was prepared in the lab .

Preparation of Colloids .

a) Preparation of Lyophilic Sols

EXPT: NO: 2

Preparation Of Colloidal Starch(Lyophilic Sols)

AIM:

To prepare a colloidal sol of starch.

Material Required:

250 mL beaker,50 mL beaker,Glassrod,Funnel,Filter-paper,Pestle and

mortar,Tripodstand,Wire-gauze,and Bunsen burner.

Chemical Required:

Soluble starch ,and Distilled water.

THEORY:

Starch forms a lyophilic sol with water which is the dispersion medium. The sol of

starch can be prepared by water to about 1000C. The sol is quite stable and is not

affected by the presence of an electrolytic impurity.

Procedure

1. Take 1 g of soluble starch in 50mL of beaker

2. Add few drops of distilled water and make a thin paste.

3. Take about 100 mL of distilled water in a 250 mL beaker

4. Heat the beaker till the water starts to boil.

5. Pour the starch paste slowly into the boiling water while stirring using a glass

rod.

6. Continue boiling for about 2-5 minutes and then allow the beaker to cool.

7. Filter the contents of the beaker, through a filter paper fixed in a funnel ,

8. Collect the filtrate.

9. Label the filtrate as Starch Sol.

Precautions:

1. The apparatus used for preparing the sol should be properly cleaned.

2. Distilled water should be used for preparing sols in water.

3. Starch should be converted into a fine paste before adding to boiling water.

4. Starch paste should be added in a thin stream to boiling water.

5. Constant stirring of the contents is necessary during the preparation of the sol.

Result :

Colloidal sol of starch has been prepared.

b)Preparation of Lyophobic Sol:

EXPT: NO: 3

PREPARATION OF FERRIC HYDROXIDE SOL AND

Aim :

1. To prepare a ferric hydroxide sol

Material Required:

conical flask,250 mL beaker, Glass tube,Funnel,Dropper,RB flask ,Iron stand with

clamp, Wire

gauze, Tripod stand,andBunsen burner.

Chemical Required:

2% solution of ferric chloride,Distilled water,

THEORY:

1. Ferric hydroxide forms a Lyophobic sol with water which is the dispersion

medium.

2. It is a irreversible sol,It is prepared by the hydrolysis of ferric chloride with

boiling distilled water as per the reaction:

3. FeCl3 (aq) + 3H2O → Fe(OH)3 + 3HCl (aq).

4. The HCl formed during the reaction tries to destabilize the sol.

5. A wine red sol of ferric hydroxide is obtained.

Procedure :

1. Take a 250 mL distilled water in

2. Bring the water to boil by placing the flask over a Bunsen burner.

3. Add ferric chloride solution dropwise to the boiling water using a dropper.

4. Continue heating until a deep red or brown solution of ferric hydroxide is

obtained.

5. The solis cooled.

Precaution :

1. Replace the water lost by evaporation during boiling at regular intervals.

2. Add ferric chloride solution dropwise.

Result :

A red colouredpositively charged ferric hydroxide sol is obtained.

PREPARATION OF ORGANIC COMPOUNDS

EXPT: NO: 4

1. Preparation of Dibezal acetone

AIM: To prepare Dibezal acetone

Material Required:

Conical Flask ,Beaker,testtube,funnel,and filter paper,

Chemical Required:

Benzaldehyde,acetone,solid NaOH and ethanol.

Theory :

Dibenzalacetone [ 1,4-pentadien-3-one, 1,5-diphenyl-]

is prepared by condensation of acetone with two equivalent of benzaldehyde.

Procedure:

1. 3mL of benzaldehyde is added with 0.9mL of acetone in a conical flask A .

2. 2.5g of solid NaOH is then dissolved in 25mL of water and 25mL of ethanol in

another conical flask B.

3. Add the content of flask B with the flask A,.

4. The mixture is corked and shaken vigorously for10 minutes,

5. Then allow standing for 15minutes, and then cooling it in ice water.

6. The yellow precipitate is formed,

7. Filter the contents of the flask through a filter paper fixed in a funnel ,


9. Label the filtrate as Dibezal acetone.

Precaution :

1. Acetone is flammable and irritating.

2. Benzaldehyde is toxic and a suspected carcinogen.

3. Aqueous sodium hydroxide is corrosive and toxic. Prevent eye, skin, and

clothing contact.

4. Wash your hands thoroughly with soap or detergent before leaving the

laboratory.

Result :

Yellow coloured crystals of dibenzal acetone are obtained.

EXPT: NO: 5

2.Preparation acetanilide from aniline.

AIM: To prepare acetanilide from aniline.

Material Required:

Conical Flask, Beaker, test tube,funnel,and filter paper,

Chemical Required:

Aniline, Acetic anhydride, and Glacial acetic acid.

Theory :

Acetanilide can be prepared by treating acetic anhydride with aniline in presence of

glacial acetic acid

Equation :

C6H5NH2 + (CH3CO)2O → C6H5NHCOCH3 + CH3COOH

Procedure

1. Take 10mL of acetic anhydride in a clean dry 250mL flask

2. Add 10mL of glacial acetic acid.

3. Shake the contents thoroughly.

4. To this mixture add 10mL of aniline

5. Boil this mixture over a sand bath for 10min.

6. Pour the liquid from the RB flask into 200mL ice-cold water taken in a

beaker.

7. While adding stir the contents of the beaker vigorously using a glass rod.

8. The white precipitate are formed,

9. Filter the contents of the flask through a filter paper fixed in a funnel ,


11. Label the filtrate as Acetanilide.

Result : --------colour of Acetanilide is prepared in the lab.

Chemical Kinetics

EXPT: NO: 6

STUDY THE EFFECT OF CONCENTRATION AND TEMPERATURE ON THE

REACTION BETWEEN SODIUM THIOSULPHATE AND HYDROCHLORIC

ACID.

Aim:

To study the effect of concentration and temperature on the reaction between sodium

thiosulphate and hydrochloric acid.

Principle:

The concentration of reacting substances affect their closeness to one another, and

consequently the frequency of their collision .

This ultimately affects the rate of reaction. The higher the concentration of reactants,

the greater the rate of reaction and vice-versa.

When the temperature of a reacting system is increased by way of heating,

The reacting particles gain energy and are able to move faster, resulting in increased

collisions, which increases the rate of the reaction.

Procedure1:

Effect of change in concentration:

1. Take 50 mL of 0.1M sodium thiosulfate solution in a conical flask

2. Add 10 mL of dilute hydrochloric acid and immediately start the clock

3. Shake the contents,

4. Place this conical flask on a piece of paper/title marked with a cross

5. Look down at the cross from above.

6. When the cross disappears to stop the clock and note the time.

7. Record this in the table.

8. Repeat the experiment using different volumes of the sodium thiosulfate

solution with water.

Observation table1 :

STUDY THE EFFECT OF CONCENTRATION ON THE REACTION BETWEEN

SODIUM THIOSULPHATE AND HYDROCHLORIC ACID:

No

Volume of

HCl in

mL.

Volume of

sodium

thiosulphatein

mL.

Volume of

water in

mL.

Concentration

of solution in

M.

The time taken

by cross to be

disappear in sec.

1. 10 50 0 0.05

2. 10 40 10 0.04

3. 10 30 20 0.03

4. 10 20 30 0.02

5. 10 10 40 0.01

Graph 1:

Rate of reaction VS Concentration:

Result :

The graph between l/t v/s volume of Na2S2O3 Or Concn of Na2S2O3 is straight line. As

concentration of Na2S2O3 increases, the rate of the reaction increases.

Procedure2:

Effect of change in temperature :

1. Take 25mL of sodium thiosulfate solution and 25mL of water into a conical

flask.

2. Add 10mL of dilute hydrochloric acid to it at room temperature and

immediately start the clock

3. Shake the contents

4. Place this conical flask on a piece of paper/title marked with a cross

5. Look down at the cross from above.

6. When the cross disappears, stop the clock and note the time taken

7. Record this in the table.

8. Repeat the experiment for( t+10), ( t+20),and ( t+30).

Observation table 2 :

STUDY THE EFFECT OF Temperature ON THE REACTION BETWEEN

SODIUM THIOSULPHATE AND HYDROCHLORIC ACID:

No

Volume of

HCl in

mL.

Volume of

sodium thio

sulphate in

mL.

Temperature in 0c

.

Time taken

by the cross

to disappear

in sec.

1/t in sec -1

1. 10 50

2. 10 50

3. 10 50

4. 10 50

5. 10 50

Graph11

Rate of reaction VS temperature

Result :

Rate of reaction is found to be

a) increases with increase in temperature.

b) increases with increase in concentration.

EXPT : 7

Chromatography

AIM:

To study the separation of pigments from extracts of leaves and flowers by paper

chromatography and determination of Rf values.

Apparatus required:

Chromatography jar with cork and hook, strip of filter paper-6 mm × 8cm, Pasteur

pipette, leaf/flower/ink and black permanent marking pen.

Chemicals required:

Ethanol

Procedure:

1. Use a black permanent marking pen to make a small ink dot about5 cm away from

one edge of the 8cm long strip of filter paper or put spots of extracts of leaves, flower

etc. Mount it on the hook of the cork to be placed on the mouth of the chromatography

jar.

2. Transfer 5 to 6 mL of ethanol into the jar.

3. Carefully insert the filter paper into the jar so that the lower end below the masks

dip in ethanol.

4. Wait for about 10 minutes.

5. Repeat steps 1 to 3 as in part 1, using a new strip of filter paper and water as the

solvent.

6. Wait for about 10 minutes.

7.Calculate Rf values.

Result:

EXPT:8

VOLUMETRIC ANALYSIS

1. To prepare 100mL of 1/20 M solution of ferrous ammonium sulphate (Mohr’s salt)

solution and using this standard solution determine the molarity and strength of given

KMnO4 solution.

Aim: Preparation of 100mL of M/20 Mohr’s salt solution and determination of molarity and

strength of given KMnO4 solution.

Materials required : Watch glass, Beaker, Burette, Pipette, Conical flask, Wash bottle,

Measuring flask, Funnel, Mohr’s salt, Distilled water and Glass rod.

Equations involved:

Reduction half equation: MnO4- + 5e- + 8H+ Mn2+ + 4H2O

Oxidation half equation: 5 Fe2+ 5Fe3+ + 5e-

Net ionic equation: MnO4- +5 Fe2+ + 8H+ Mn2+ + 5Fe3+ +4H2O

Indicator: KMnO4 is a self indicator

End point: appearance of colourless to pale permanent pink

Procedure:

1. The weighed 1.96 g of Mohr’s salt is transferred to 100mL measuring flask with the

help of funnel.

2. Distilled water is used to dissolve the Mohr’s salt with little amount of dilute sulphuric

acid and made into 100mL by adding more water.

3. Pipette was rinsed with Mohr’s salt solution and 20 mL of this solution was pipetted

out into a conical flask and one test tube of dilute sulphuric acid was added.

4. Burette was rinsed and filled with given KMnO4 solution using funnel and adjusted to

zero mark.

5. Burette solution KMnO4 was opened and titrated against Mohr’s salt solution in the

conical flask till the end point of appearance of permanent pale pink colour.

6. Noted the burette reading and repeated the titration in the same manner till the

concordant readings obtained.

Results:

Molarity of given KMnO4 solution=--------------------mol/L

Strength of given KMnO4 solution=--------------------g/L

Observations and Calculations:

Preparation of 1/20M Mohr’s salt solution:

Calculation of weight of Mohr’s salt required in making 100mL of 1/20M solution

Weight of Mohr’s salt required = 𝑀𝑉𝑆/1000

M= Molecular mass of Mohr’s salt (392)

V= Volume required (100 mL)

S= Molarity (1/20)

Weight of empty watch glass =-------------------(w1) g

Weight of watch glass + Mohr’s salt =--------------------(w2) g

Weight of Mohr’s salt = (w2 – w1)g

Volume of solution prepared = 100mL

Molarity of Mohr’s salt solution =

Titration of Mohr’s salt and KMnO4: (Simple Procedure)

Burette solution: KMnO4

Pipette solution: Mohr’s salt solution

Medium: acidic medium(dil.H2SO4)

Indicator: KMnO4 (self)

Temperature: Room temperature

End point :Appearance of permanent pale pink colour.

Observation:

S.NO Volume of

Mohr’s salt

solution mL

BURETTE READING(KMnO4) (mL) Volume of

KMnO4 solution

used mL INITIAL FINAL

1

2

3

Calculations:

a1 x M1 x V1 (Mohr’s salt solution)= a2 x M2 x V2 (KMnO4 solution)

No of electrons lost by Mohrs’salt( a1) = 1

No of electrons gained by KMnO4 ( a2)= 5

Molarity of Mohr’s salt solution ( M1)=

Volume of Mohr’s salt solution ( V1)=

Molarity of KMnO4 solution ( M2)=

Volume of KMnO4 solution ( V2)=

Substituting the value of a1 and a2 in above equation

1 x M1 x V1 (Mohr’s salt solution) = 5 x M2 x V2 (KMnO4 solution)


Strength of KMnO4 solution = Molarity x Molecular mass of KMnO4

= -----------------------g/L

EXPT: 9

VOLUMETRIC ANALYSIS

To prepare 100mL of 1/20 M solution of Oxalic acid solution and using this standard

solution determine the molarity and strength of given KMnO4 solution.

Aim: Preparation of 100mL of 1/20 M solution of Oxalic acid solution and determination of

molarity and strength of given KMnO4 solution.

Materials required : Watch glass, Beaker, Burette, Pipette, Conical flask, Wash bottle,

Measuring flask, Funnel, Oxalic acid , Distilled water and Glass rod.

Equations involved:

Reduction half equation: 2MnO4- + 10e- + 16H+ 2Mn2+ + 8H2O

Oxidation half equation: 5 C2O42- 10CO2 + 10e-

Net ionic equation: 2 MnO4- +5 C2O4

2- +16H+ 2Mn2+ + 10CO2 + 8H2O

Indicator: KMnO4 is a self indicator

End point: Appearance of colourless to pale permanent pink

Procedure:

1. The weighed 0.63 g of Oxalic acid is transferred to 100mL measuring flask with the

help of funnel.

2. Distilled water is used to dissolve the Oxalic acid and made into 100mL by adding

more water.

3. Pipette was rinsed with Oxalic acid solution and 20 mL of this solution was pipetted

out into a conical flask and one test tube of dilute sulphuric acid was added.

4. The titre mixture was warmed to 60- 700C.

5. Burette was rinsed and filled with given KMnO4 solution using funnel and adjusted to

zero mark.

6. Burette solution KMnO4 was titrated against standard Oxalic acid solution in the

conical flask till it reaches the end point of the appearance of pale permanent pink

colour.

7. Noted the burette reading and repeated the titration in the same manner till the

concordant readings are obtained.

Results:

Molarity of given KMnO4 solution=--------------------mol/L

Strength of given KMnO4 solution=--------------------g/L

Observations and Calculations:

Preparation of 1/20M Oxalic acid solution:

Calculation of weight of Oxalic acid required in making 100mL of 1/20M solution

weight of Oxalic acid required = 𝑀𝑉𝑆/1000

M= Molecular mass of Oxalic acid (126)

V= Volume required (100 mL)

S= Molarity (1/20)

Weight of empty watch glass =-------------------w1 g

Weight of watch glass + Oxalic acid =--------------------w2 g

Weight of Oxalic acid = (w2 – w1)g

Volume of solution prepared = 100mL

Molarity of Oxalic acid solution =

Titration of Oxalic acid and KMnO4: (Simple Procedure)

Burette solution: KMnO4

Pipette solution: Oxalic acid solution

Indicator: KMnO4 (self)

Medium: acidic medium(dil.H2SO4)

Temperature: 60- 700C

End point : Appearance of permanent pale pink colour.

Observation:

S.NO Volume of

Oxalic acid

solution (mL)

BURETTE READING(KMnO4) (mL) Volume of

KMnO4 solution

used (mL) INITIAL FINAL

1

2

3

Calculations:

a1 x M1 x V1 (Oxalic acid solution)= a2 x M2 x V2 (KMnO4 solution)

No of electrons lost by Oxalic acid ( a1) =2

No of electrons gained by KMnO4 ( a2)= 5

Molarity of Oxalic acid solution ( M1)=

Volume of Oxalic acid solution ( V1)=


Volume of KMnO4 solution ( V2)=

Substituting the value of a1 and a2 in above equation

2 x M1 x V1 (Oxalic acid solution) = 5 x M2 x V2 (KMnO4 solution)


Strength of KMnO4 solution = Molarity x Molecular mass of KMnO4

= -----------------------g/L

Qualitative Analysis

Qualitative Analysis of simple salt-1 (Calcium Carbonate)

Experiment Observation Inference

1. Preliminary Test:

Note the colour of the

sample.

Colourless

Absence of

copper,nickel,ferrous,ferric

and cobalt.

Solubility test:

Added distilled water to

the salt taken in a clean

dry test tube.

The salt was insoluble.

Absence of ammonium

carbonate.

Ash test:

Added one drop of dil.

Cobalt nitrate and

con.HNO3 to the salt

solution. Dip a filter

paper and burn it.

No characteristic colour

of ash.

Absence of aluminium,

Zinc and magnesium.

Flame test:

Made a paste of the salt

with conc.HCl in a

watch glass. Introduced

a small part of the paste

into the blue part of

flame by a glass rod.

A brick red flame was

obtained.

Presence of calcium is

indicated.

Copper turnings test:

Added copper turnings

and conc.H2SO4 to the

salt taken in a test tube.

No reddish-brown fumes. Absence of nitrate.

Dry test for Acid Radical:

Added dil. H2SO4 to the


A colourless gas evolved

with brisk effervescence.

Presence of carbonate is

indicated.

Conc. H2SO4 test:

Add a pinch of salt with

conc. H2SO4 taken in

the test tube and heat it.

No characteristic change.

Absence of chloride,

bromide, iodide, nitrate,

acetate and oxalate.

Test for sulphate ion:

Barium chloride test: No characteristic Absence of sulphate.

Add a small amount of

salt with dil. HCl and

added a few drops of

BaCl2 solution.

precipitate.

Test for Phosphate ion:

Added conc. HNO3 to

the salt, boil the

contents and added the

excess of ammonium

molybdate solution.

No characteristic

precipitate.

Absence of Phosphate.

Confirmatory test for Carbonate ion:



A colourless gas

evolved with brisk

effervescence which

turns lime water

milky.

Presence of carbonate is

confirmed.

Test for cations (Basic Radicals)

Inter Group separation:

Preparation of Original solution (O.S):

Prepare salt solution by dissolving in dil. HCl.

Test for group 0-

Ammonium

The solid salt is heated

with conc. NaOH

solution.

No characteristic

odour.

Absence of Ammonium ion.

Intergroup Separation

To the original salt

solution (OSS) added

dil. HCl.

No characteristic

precipitate.

Absence of Group I (Lead)

To OSS added dil. HCl

and passed H2S

No characteristic

precipitate.

Absence of Group II radicals

(Copper, Cadmium)

To OSS added solid

NH4Cl, boil and cool

then add NH4OH

solution in excess

No characteristic

precipitate.

Absence of Group III radicals

(Aluminium, Iron)

To OSS added solid


then add NH4OH

solution in excess and

pass H2S gas.

No characteristic

precipitate.

Absence of Group IV radicals

(Zinc and Manganese)

To OSS added solid


then add NH4OH


add ammonium

A white precipitate

was obtained

Presence of Group V radicals

(Barium, Strontium, Calcium)

RESULT:

Hence the given salt contains

Acid radical: Carbonate ion

Basic radical: Calcium ion

****

carbonate solution.

Confirmatory Tests for Group V Radicals:

Dissolve the white precipitate in hot dil. CH3COOH and divided the solution into

3 parts.

Test for Barium ion:

To one part of the

solution added

potassium chromate

solution.

No characteristic

precipitate.

Absence of Barium ion.

Test for Strontium ion:

To the second part of

the solution added

Ammonium sulphate

(NH4)2SO4 solution

No characteristic

precipitate.

Absence of strontium ion.

Test for Calcium ion:

To the third part of the

solution, added

ammonium oxalate

solution

A white precipitate is

formed

Presence of Calcium ion is

confirmed.

Qualitative Analysis of simple salt-2 (Aluminium Sulphate)




sample

Colourless

Absence of


and cobalt.

Solubility test:



dry test tube.

The salt was soluble.

Absence of heavy metal

carbonates.

Ash test:


Cobalt nitrate and



paper and burn it.

Blue coloured ash is

obtained.

Presence of aluminium

ion.

Flame test:


with conc.HCl in a





No characteristic flame is

obtained

Absence of calcium,

barium, strontium and

copper is indicated.







Dil. H2SO4 test:



No characteristic change. Absence of carbonate,

sulphide, sulphite and

nitrite.

Conc. H2SO4 test:









Barium chloride test:




BaCl2solution.

A white precipitate

which is insoluble in

conc. HCl is obtained.

Presence of sulphate is

indicated.


Added conc. HNO3 to

the salt, boil the


excess of ammonium

molybdate solution.

No characteristic

precipitate.


Confirmatory test for Sulphate ion:





BaCl2solution.

A white precipitate




confirmed.

Lead acetate test:


salt with dil. Actic acid

and add Lead acetate

solution.

A white precipitate

was obtained.


confirmed.




Prepare salt solution by dissolving in distilled water.

Test for group 0-

Ammonium


with conc. NaOH

solution.

No characteristic

odour.





dil. HCl.

No characteristic

precipitate.



and passed H2S

No characteristic

precipitate.


(Copper, Cadmium)

To OSS added solid


then add NH4OH

solution in excess.

A gelatinous white

precipitate.

Presenceof Group III radicals

(Aluminium)

Confirmatory Tests for Group III Radicals:

Dissolve the white precipitate in dil. HCl and divide into two parts.

Test for Aluminium ion:

RESULT:


Acid radical: Sulphate ion

Basic radical: Aluminium ion

****

Qualitative Analysis of simple salt-3(Lead acetate)

Lake test:

To the first part add 2

drops of blue litmus

solution followed by the

addition of the NH4OH

solution till blue colour

develops.

Blue precipitate

floating in the

colourless solution is

obtained.

Presence of Aluminium ion is

confirmed.

To the second part add

dil. NaOH in drops.

White precipitate

dissolves in excess

NaOH.

Presence of Aluminium ion is

confirmed.




sample

Colourless

Absence of


and cobalt.

Solubility test:



dry test tube.



carbonate.

Ash test:


Cobalt nitrate and



paper and burn it.

No characteristic

coloured ash is obtained.


Zinc and Magnesium.

Flame test:


with conc.HCl in a






obtained

Absence of calcium,









Dil. H2SO4 test:





nitrite.

Conc. H2SO4 test:




Colourless gas with a

characteristic smell of

vinegar.

Presence of acetate ion.

Test for acetate ion:

Ester test:




Add about 1 mL of

ethanol, shake and pour

the contents of test tube

in a beaker full of water

and stir it.

Pleasant fruity smell of

ester is observed.

Presence of acetate ion is

indicated.






BaCl2solution.

No characteristic

precipitate.

Absenceof sulphate ion.


Added conc. HNO3 to

the salt, boil the


excess of ammonium

molybdate solution.

No characteristic

precipitate.


Confirmatory test for acetate ion:

Ester test:




Add about 1 mL of

ethanol, shake and pour

the contents of test tube

in a beaker full of water

and stir it.

Pleasant fruity smell

of ester is observed.


confirmed.

Ferric chloride test:

To the aqueous solution

of salt add ferric

chloride solution. Filter

and divide the filtrate in

2 portions.

(i) To one part add dil

HCl

(ii) To second part add

water and boil it.

Appearance of red

precipitate.

Red colour

disappears.

Reddish brown

precipitate is formed.


confirmed.


confirmed.




Prepare salt solution by dissolving in hot water.

Test for group 0-

Ammonium


with conc. NaOH

solution.

No characteristic

odour.





dil. HCl.

white precipitate is

obtained.

Presence of Group I (Lead)

Confirmatory Tests for Group I Radical:

Boil the white precipitate with 5-10 mL of water and divide into two parts.

Test for lead ion:

Potassium Iodide Test:



potassium iodide (KI)

solution

A yellow precipitate

which dissolves on

heating with water

and reappears as

golden spangles on

cooling.

Presence of Lead ion is

confirmed

Potassium Chromate

Test: To the original

A yellow precipitate

was obtained

Presence of Lead ion is

confirmed

RESULT:


Acid radical: Acetate ion

Basic radical: Lead ion

****

Qualitative Analysis of simple salt-4 (Zinc Sulphide)

salt solution (OSS)

added K2CrO4 solution




sample

Colourless

Absence of


and cobalt.

Solubility test:



dry test tube.

The salt was insoluble.

Absence of ammonium

carbonate.

Ash test:


Cobalt nitrate and



paper and burn it.

Appearance of green

colour ash.

Presence of Zinc ion is

Flame test:


with conc.HCl in a





No characteristic flame.

Absence of calcium,











Colourless gas, smells

like rotten egg(H2S)

turns lead acetate paper

to black.

Presence of sulphide is

indicated.






BaCl2 solution.

No characteristic

precipitate.

Absence of sulphate.


Added conc. HNO3 to

the salt, boil the


excess of ammonium

molybdate solution.

No characteristic

precipitate.


Preparation of Sodium carbonate extract:

Since, salt is insoluble in water, sodium carbonate extract was prepared by

boiling 1 g of salt ith 2 g of sodium carbonate in 20 mL of distilled water. The

filtrate is taken for the confirmatory test.

Confirmatory test for sulphide ion:

Sodium nitroprusside

test:

The above extract,


sodium nitroprusside

solution.

Violet colour is

obtained.


confirmed.

Lead acetate test:

To the above extract,


lead acetate solution.

A black precipitate is

obtained.


confirmed.




Prepare salt solution by dissolving in water.

Test for group 0-

Ammonium


with conc. NaOH

solution.

No characteristic

odour.


RESULT:


Acid radical: Sulphide ion

Basic radical: Zinc ion

****




dil. HCl.

No characteristic

precipitate.



and passed H2S

No characteristic

precipitate.


(Copper, Cadmium)

To OSS added solid


then add NH4OH

solution in excess

No characteristic

precipitate.


(Aluminium, Iron)

To OSS added solid


then add NH4OH


pass H2S gas.

A dirty white

precipitate is obtained.

Presence of Group IV radicals

(Zinc)

Confirmatory Tests for Group IV Radicals:

Dissolve the dirty white precipitate in hot dil. HCl and divided the solution into 2

parts.

Test for Zinc ion:

Sodium hydroxide

test:



Sodium hydroxide

(NaOH) in drops.

A white brown

precipitate was

formed which

dissolves in excess of

NaOH.


confirmed.

Potassium Ferro

cyanide test:



potassium Ferro cyanide

solution

A pale blue precipitate

was obtained


confirmed

Qualitative Analysis of simple salt-5 (Ammonium Phosphate)




sample

Colourless

Absence of


and cobalt.

Solubility test:



dry test tube.



carbonates.

Ash test:


Cobalt nitrate and



paper and burn it.


of ash.


Zinc and magnesium.

Flame test:


with conc.HCl in a






obtained

Absence of calcium,









Dil. H2SO4 test:





nitrite.

Conc. H2SO4 test:









Barium chloride test: No characteristic Absence of sulphate.




BaCl2 solution.

precipitate.


Added conc. HNO3 to

the salt, boil the


excess of ammonium

molybdate solution.

A deep yellow precipitate

or colouration is formed.

Presence of Phosphate is

indicated.

Confirmatory test for Carbonate ion:

Added conc. HNO3 to

the salt, boil the


excess of ammonium

molybdate solution.

A deep yellow precipitate

or colouration is formed.

Presence of Phosphate is

confirmed.




Prepare salt solution by dissolving in distilled water..




dil. HCl.

No characteristic

precipitate.



and passed H2S

No characteristic

precipitate.

Absence of Group II

radicals (Copper,

Cadmium)

To OSS added solid


then add NH4OH

solution in excess

No characteristic

precipitate.

Absence of Group III

radicals (Aluminium, Iron)

To OSS added solid


then add NH4OH


pass H2S gas.

No characteristic

precipitate.

Absence of Group IV

radicals (Zinc and

Manganese)

To OSS added solid


then add NH4OH


add ammonium

carbonate solution.

No characteristic

precipitate.

Absence of Group V

radicals (Barium,

Strontium, Calcium)

To OSS added solid


then add NH4OH

No characteristic

precipitate.

Absence of Group VI

radicals (Magnesium)

RESULT:


Acid radical: Phosphate ion

Basic radical: Ammonium ion

****

Qualitative Analysis of simple salt-6 (Barium nitrate)


add ammonium

Phosphate solution.

Test for group Zero:

Ammonium


with conc. NaOH

solution.

Evolution of NH3 gas

with ammoniacal odour.

Presence of Ammonium

ion.

Confirmatory Tests for Group Zero Radicals:

Test for Ammonium ion:


with conc. NaOH

solution.

Evolution of NH3 gas

with ammoniacal odour,

when passed through

Nessler’s reagent forms

brown precipitate.

Presence of Ammonium

ion is confirmed.




sample

Colourless

Absence of


and cobalt.

Solubility test:



dry test tube.



carbonates.

Ash test:


Cobalt nitrate and



paper and burn it.


of ash.


Zinc and magnesium.

Flame test:


with conc.HCl in a





An apple green flame

was obtained.

Presence of Barium is

indicated.





Evolution of reddish-

brown fumes.

Presence of nitrate is

indicated.






nitrite.

Conc. H2SO4 test:




Evolution of reddish

brown gas with pungent

smell, turns ferrous

sulphate black.


indicated.






BaCl2 solution.

No characteristic

precipitate.



Added conc. HNO3 to

the salt, boil the


excess of ammonium

molybdate solution.

No characteristic

precipitate.


Confirmatory test for nitrate ion:

Brown ring test:

Acidified the extract

with dil. H2SO4 and

added freshly prepared

ferrous sulphate

solution and then

conc.H2SO4 along the

A brown ring was

formed at the junction

of the two layers.


confirmed.

sides of the test tube.





Test for group 0-

Ammonium:


with conc. NaOH

solution.

No characteristic

odour.





dil. HCl.

No characteristic

precipitate.



and passed H2S

No characteristic

precipitate.


(Copper, Cadmium)

To OSS added solid


then add NH4OH

solution in excess

No characteristic

precipitate.


(Aluminium, Iron)

To OSS added solid


then add NH4OH


pass H2S gas.

No characteristic

precipitate.



To OSS added solid


then add NH4OH


add ammonium

carbonate solution.

A white precipitate

was obtained





3 parts.


To one part of the

solution added

potassium chromate

solution.

A yellow precipitate is

formed.

Presence of Barium ion is

confirmed.


the solution added

Ammonium sulphate

(NH4)2SO4 solution


formed.


confirmed.


solution, added


formed.


confirmed.

RESULT:


Acid radical: Nitrate ion

Basic radical: Barium ion

****

Qualitative Analysis of simple salt-7 (Magnesium Sulphate)

ammonium oxalate

solution




sample

Colourless

Absence of


and cobalt.

Solubility test:



dry test tube.



carbonate.

Ash test:


Cobalt nitrate and



paper and burn it.

Pinkcoloured ash is

obtained.

Presence of Magnesium

ion.

Flame test:


with conc.HCl in a






obtained

Absence of calcium,









Dil. H2SO4 test:





nitrite.

Conc. H2SO4 test:













BaCl2solution.

A white precipitate




indicated.


Added conc. HNO3 to

the salt, boil the


excess of ammonium

molybdate solution.

No characteristic

precipitate.







BaCl2solution.

A white precipitate




confirmed.

Lead acetate test:


salt with dil. Acetic acid


solution.

A white precipitate

was obtained.


confirmed.





Test for group 0-

Ammonium


with conc. NaOH

solution.

No characteristic

odour.



To the original salt No characteristic Absence of Group I (Lead)

RESULT:


Acid radical: Sulphate ion

Basic radical: Magnesium ion


dil. HCl.

precipitate.


and passed H2S

No characteristic

precipitate.


(Copper, Cadmium)

To OSS added solid


then add NH4OH

solution in excess.

No characteristic

precipitate.


(Aluminium and Iron.)

To OSS added solid


then add NH4OH


pass H2S gas.

No characteristic

precipitate.



To OSS added solid


then add NH4OH


add ammonium

carbonate solution.

No characteristic

precipitate.

Absence of Group V radicals


To OSS added solid


then add NH4OH


add ammonium

Phosphate solution.


obtained.

Presence of Group VI radicals

(Magnesium)

Confirmatory Tests for Group VI Radical:

Dissolve the white precipitate in NH4OH and divide into two parts.

Test for Magnesium ion:

To the first part add

Sodium Carbonate

solution


obtained

Presence of Magnesium ion is

confirmed.

To the second part add

few drops of Magneson

reagent.

A blue precipitate is

obtained

Presence of Magnesium ion is

confirmed.

****

Qualitative Analysis of simple salt-8 (Manganese chloride)




sample

Light pink is colour.

Presence of Manganese is

indicated.

Solubility test:



dry test tube.



carbonate.

Ash test:


Cobalt nitrate and



paper and burn it.


of ash.


Zinc and magnesium.

Flame test:


with conc.HCl in a





No characteristicflame

was obtained.

Absence of calcium,













nitrite.

Conc. H2SO4 test:




Colourless gas with

pungent smell gives

dense white fumes with

the glass rod dipped with

NH4OH and gives a

white precipitate with

AgNO3 solution.

Presence of chloride is

indicated.

Test for Chloride ion:

Silver nitrate test:

Acidified the aqueous

solution of the salt with

dil. HNO3 and added

AgNO3 solution.

A curdy white precipitate

is formed which is

soluble in NH4OH.

Presence of chloride ion is

confirmed.






BaCl2 solution.

No characteristic

precipitate.



Added conc. HNO3 to

the salt, boil the


excess of ammonium

molybdate solution.

No characteristic

precipitate.


Confirmatory test for Chloride ion:




dil. HNO3 and added

AgNO3 solution.

A curdy white

precipitate is formed

which is soluble in

NH4OH.


confirmed.





Test for group 0-

Ammonium


with conc. NaOH

solution.

No characteristic

odour.





dil. HCl.

No characteristic

precipitate.



and passed H2S

No characteristic

precipitate.


(Copper, Cadmium)

To OSS added solid


then add NH4OH

solution in excess

No characteristic

precipitate.


(Aluminium, Iron)

To OSS added solid


A buff coloured


Presence of Group IV radical.

(Manganese)

RESULT:


Acid radical: Chloride ion

Basic radical: Manganese ion

****

Qualitative Analysis of simple salt-9 (Strontium chloride)

then add NH4OH


pass H2S gas.

Confirmatory Tests for Group IV Radicals:

Dissolve the buff coloured precipitate in hot dil. HCl and boil off H2S.

Test for Manganese ion:

Sodium hydroxide-

Bromine test:

To the above solution

add NaOH solution and

shake.

A white precipitate id

formed followed by

the addition of

bromine water turns to

black.

Presence of Manganese ion is

confirmed.




sample

Colourless

Absence of


and cobalt.

Solubility test:



dry test tube.



carbonate.

Ash test:


Cobalt nitrate and



paper and burn it.


of ash.


Zinc and magnesium.

Flame test:


with conc.HCl in a





A crimson red flame was

obtained.

Presence of strontium is

indicated.











nitrite.

Conc. H2SO4 test:




Colourless gas with

pungent smell gives

dense white fumes with

the glass rod dipped with

NH4OH and gives a

white precipitate with

AgNO3 solution.

Presence of chloride is

indicated.

Test for Chloride ion:




dil. HNO3 and added

AgNO3 solution.

A curdy white precipitate

is formed which is

soluble in NH4OH.


confirmed.






BaCl2 solution.

No characteristic

precipitate.



Added conc. HNO3 to

the salt, boil the


excess of ammonium

molybdate solution.

No characteristic

precipitate.


Confirmatory test for Chloride ion:




A curdy white

precipitate is formed

which is soluble in


confirmed.

dil. HNO3 and added

AgNO3 solution.

NH4OH.





Test for group 0-

Ammonium


with conc. NaOH

solution.

No characteristic

odour.





dil. HCl.

No characteristic

precipitate.



and passed H2S

No characteristic

precipitate.


(Copper, Cadmium)

To OSS added solid


then add NH4OH

solution in excess

No characteristic

precipitate.


(Aluminium, Iron)

To OSS added solid


then add NH4OH


pass H2S gas.

No characteristic

precipitate.

Absence of Group IV radical.

(Manganese and Zinc)

To OSS added solid


then add NH4OH


add ammonium

carbonate solution.


obtained.





3 parts.


To one part of the

solution added

potassium chromate

solution.

No characteristic

precipitate.

Absence of Barium ion.

Test for Strontium ion:


the solution added

Ammonium sulphate

(NH4)2SO4 solution


formed

Presence of strontium ion is

confirmed.

RESULT:


Acid radical: Chloride ion

Basic radical: Strontium ion

Qualitative Analysis of simple salt-10 (Nickel Sulphate)


solution, added

ammonium oxalate

solution


formed

Presence of strontium ion is

confirmed.




sample

Green in colour.

May be the presence of

Nickel.

Solubility test:



dry test tube.



carbonate.

Ash test:


Cobalt nitrate and



paper and burn it.

No characteristic ash is

obtained


Zinc and magnesium.

Flame test:


with conc.HCl in a






obtained

Absence of calcium,









Dil. H2SO4 test:





nitrite.

Conc. H2SO4 test:













BaCl2solution.

A white precipitate



Presenceof sulphate is

indicated.


Added conc. HNO3 to

the salt, boil the


excess of ammonium

molybdate solution.

No characteristic

precipitate.







BaCl2solution.

A white precipitate




confirmed.

Lead acetate test:


salt with dil. Acetic acid


solution.

A white precipitate

was obtained.


confirmed.





Test for group 0-

Ammonium


with conc. NaOH

solution.

No characteristic

odour.



To the original salt No characteristic Absence of Group I (Lead)

RESULT:


Acid radical: Sulphate ion.

Basic radical: Nickel ion.


dil. HCl.

precipitate.


and passed H2S

No characteristic

precipitate.


(Copper, Cadmium)

To OSS added solid


then add NH4OH

solution in excess.

No characteristic

precipitate.


(Aluminium and Iron.)

To OSS added solid


then add NH4OH


pass H2S gas.

A black precipitate is

obtained

Presence of Group IV radicals

(Nickel)

Confirmatory Tests for Group IV Radical:

Test for Nickel ion:

Dimethyl glyoxime

test: To the OSS add

NH4OH solution and

few drops of dimethyl

glyoxime solution.

A bright rose red


Presence of Nickel ion is

confirmed.

EXPT:11

Food stuff Analysis

Aim:

To identify simple reactions of carbohydrates, fats, proteins, starch and

detection of their presence in given food stuff.

TEST FOR CARBOHYDRATE

S.No Experiment Observation Inference

1. Test for carbohydrates:

To aqueous solution add

few drops of molish

reagent (α- napthol and

conc H2SO4) along the

sides of test tube.

Appearance of a purple

layer at the junction of

two liquids.

Presence of

carbohydrates

(reducing and

non-reducing

sugar)

2. To another part of solution

equal amount of fehling

solution A and B are

added and heated in a

water bath.

Formation of brick red

precipitate.

Presence of

reducing sugar

(glucose).

3. To another part of solution

Benidict’s reagent is added

and kept in water bath.

Formation of brick red

precipitate.

Presence of

reducing sugar

(glucose).

4. To another part of sample,

Tollen’s reagent is added

and heated.

Shiny silver mirror is

formed on the sides of

the test tube

Presence of

reducing sugar

(glucose).

Result:

The given food sample contains carbohydrate.

TEST FOR STARCH


1. Test for Starch:

To aqueous solution of

the given sample, few

drops of iodine is added.

Blue-black colouration

is observed.

Presence of

Starch.

Result:

The given food sample contains starch.

TEST FOR PROTEIN


1. Test for Proteins:

Xanthoprotein test:

To the given sample in a

test tube. Few drops of

conc HNO3 is added and

shaken well

Yellow colouration is

obtained.

Presence of

Protein.

2. Biuret test:

To the sample biuret

solution is added.

Blue colouration is

obtained.

Presence of

Protein.

3. Ninhydrin test:

A small part of sample is

boiled with ninhydrin

reagent.

Intense blue

colouration is formed

Presence of

protein.

Result:

The given food sample contains protein.

TEST FOR FATS


1. Test for fats:

Spot test:

A drop of sample is

placed on a filter paper.

Translucent spot is

observed.

Presence of fat.

2. To a small part of the

sample added 5mL of

chloroform and divided

into 2 parts A and B

To part A add 5 mL of

water.

To part B add 2-3 drops

of iodine solution.

Separate layers are

formed

Iodine remains

undissolved

Presence of fat.

Presence of fat.

3. To the sample added

potassium bisulphite and

heated.

Irritating odour of

acrolein is formed

Presence of fat.

Result:

The given food sample contains fat.

EXPT:12

Test for functional group in organic compound

Aim:

To identify the functional group in the given sample of organic compound

TEST FOR UNSATURATION


1. Test for unsaturation:

Bromine water test:

To a small amount of

organic sample, bromine

water was added

Decolourisation of

brown colour

Presence of

unsaturated.

2. Baeyer’s test:

To a small amount of

organic compound

Baeyer’s reagent was

added

Decolourisation of pink

colour

Presence of

unsaturated

Result:

Thus the presence of unsaturation is confirmed.

TEST FOR ALCOHOLS


1. Test for Alcohols:

Ester test:

To the sample, small

amount of acetic acid was

added along with 2-3

drops of conc. H2SO4 and

warmed in a water bath.

After adding

bicarbonate to the

mixture fruity smell is

obtained

Presence of

Alcoholic group.

2. Iodoform test:

To the sample small

amount of I2 solution was

added followed by NaOH

After keeping it in on

the water bath, yellow

colour precipitate is

obtained

Presence of

Alcoholic group.

3. Lucas test:

To the sample small

amount of ZnCl2 and HCl

was added and heated

Turbidity occurs after

some time

Presence of

Alcoholic group.

Result:

Thus the presence of Alcohol is confirmed.

TEST FOR PHENOL


1. Test for Phenols:

Neutral FeCl3 test:

To the sample Neutral

FeCl3was added and

heated.

Violet colouration is

obtained

Presence of

Phenolic group.

2. Litmus test:

To the sample, blue litmus

solution is added.

Blue colour turns red.

Presence of

Phenolic group.

3. Liebermann’s test:

To the sample small

amount of NaNO2 was

added and conc. H2SO4

was added dropwise.

Mass becomes red and

blue green on the

treatment with NaOH

Presence of

Phenolic group.

Result:

Thus the presence of Phenol is confirmed.

TEST FOR ALDEHYDES


1. Test for Aldehydes:

Fehling’s test:

To the sample Fehling’s

solution and NaOH are

added and kept in the

water bath

Red precipitate is

obtained

Presence of

Aldehydic group.

2. Tollen’s test:

To the sample, Tollen’s

reagent and NaOH are

added and kept in the

water bath.

Silver mirror is

obtained on the walls of

the test tube

Presence of

Aldehydic group

3. 2,4 DNP test:

To the sample 2,4 DNP

and NaOH are added and

kept in the water bath.

Red orange precipitate

is obtained

Presence of

Aldehydic group.

Result:

Thus the presence of Aldehyde is confirmed.

TEST FOR KETONES


1. Test for Ketones:

Iodoform test:


amount of I2 solution was

added followed by NaOH

solution.

After keeping in the

water bath yellow

precipitate is obtained

Presence of

methyl ketone.

2. Sodium nitroprusside test:

To the sample, Sodium

nitroprusside and NaOH

solution.

Appearance of wine red

colour.

Presence of

ketonic group

3. 2,4 DNP test:

To the sample 2,4 DNP

and NaOH are added and

kept in the water bath.

Red orange precipitate

is obtained

Presence of

Ketonic group.

Result:

Thus the presence of Ketone is confirmed.

TEST FOR CARBOXYLIC ACID


1. Test for carboxylic acid:

Litmus test:

To the sample, blue litmus

solution is added

Blue colour turns to red

colour

Presence of

carboxylic acid.

2. Sodium bicarbonate test:

To the sample, Sodium

bicarbonate solution was

added.

Brisk effervescence

turns lime water milky.

Presence of

carboxylic group

3. Ester test:


amount of ethanol was

added along with 2-3

drops of conc. H2SO4 and

kept in the warm water

bath.

After adding

bicarbonate to the

mixture fruity smell is

evolved

Presence of

carboxylic group

Result:

Thus the presence of carboxylic acid is confirmed.

TEST FOR AMINE


1. Test for Amines:

Solubility test:

To the sample, conc. HCl

is added.

Homogeneous solution

is obtained due to the

formation of salt

Presence of

amine.

2. Litmus test:

To the sample, red litmus

solution is added

Red colour turns to blue

colour.

Presence of

amine.

3. Azo dye test:

To the sample add 1-2 mL

of dil.HCl. Cool it with ice

cold water and add 2-3 mL

aqueous solution of

sodium nitrite. Dissolve

0.2 g of β-napthol in dil

NaOH solution and add in

the above solution.

Red orange dye is

formed

Presence of

amine.

Result:

Thus the presence of amine is confirmed.

Documents

CHEMISTRY LAB MANUAL · 2020-03-23 · Benzaldehyde,acetone,solid NaOH and ethanol. Theory : Dibenzalacetone [ 1,4-pentadien-3-one, 1,5-diphenyl-] is prepared by condensation of acetone