contents

CONTENTS
Chapter-1:
Familirization of Methods for Volumetric Analysis
(or)Titrimetric Analysis
1
Chapter-2:

Preparation of Standard Sodium Carbonate Solution

(Na,CO₃) and Making Different Diluated Solutions 7-9
Chapter-3:
Estimation of HCl using Standard Na₂CO,Solution 11-14
Chapter-4:
Estimation of Sodium Hydroxide Using Standard HCl Solution · ·
15-18
Chapter-5:
Estimation of H,SO,using Standard NaOH Solution 19-22

Chapter-6:
Estimation of Mohr's Salt by Using Standard KMnO₄Solution 23-26
Chapter-7:
Determination of Acidity of Water Sample …· ·
27-30
Chapter-8:
Determination of Alkalinity of Water Sample 31-34
Chapter-9:
Determination of Total Hardness of Water Sample
35-39
using Standard EDTA Solution
Chapter-10:
41-44
Estimate of Chlorides Present in Water Sample
Chapter-11:
45-48
Estimation of Dissolved Oxygen in Water Sample * * * * * - -

Chapter-12:
49-51
Determination of p''of Water Sample using pH Meter
Chapter-13;
53-55
Determination of Conductivity of Water Sample
Chapter-14; 57-60
Determination of Turbidity of Water
Chapter-15: 61-62
Estimation of Total Solids Presents in Water Sample * 63-64
Preparation of Reagents used in Laboratory
(A.P)
. OESCRIPT/ON

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amiltrization of Methods for Volumetrlc Analysis (or)Titrimetrlc Analyslsl

Familirization of Methods for

Volumetric Analysis
(or)Titrimetric Analysis

DATE :
EXPERIMENT NO.:1

ANALYTICAL CHEMISTRY:

The branch of chemistry which deals with analysis of compound is called analytical chemistry

Analysis is divided into two types.

1.Qualitative analysis

2.Quantitative analysis.

1. Qualitative analysis:

The analysis deals with the detection and identification of constituents present in in a given
substance is called Qualitative analysis

This analysis is carried out to identify the elements or ions (cations or anions)present in
the compound or mixture of compounds by following a systematic procedure.

Ex:1.Analysis of Ammonium sulphate.(NH₄)₂(SO₄)

2.Analysis of Barium Chloride,(BaCl,),etc.

2. Quantitative analysis:

The analysis deals with the estimation of quantity of constituents present in the compound is
called quantitative analysis

Quanlitative analysis is divided into two types.

(a)Gravimetric Analysis:In this method the compound to be estimated is converted into

insoluble compound of known composition.This compound is separated,dried and weighed.

(b)Volumetric Analysis (or)Titrimetric Analysis:In this method the compound to be

estimated is allowed to react with solution of known concentration(standard solution).

The solution of accurately known concentration is called standard solution.The amount of the
subst ance to be determined is calculated from the volume of the standard solution used,the chemical
equation and relative molecular masses of the reacting substances.
Experlment-1 【A.P]
 Laboratory Manual in Chemistry

1.1 CONDITIONS AND REQUIREMENTS FOR TITRIMETRIC ANALYSIS:

、1.The reaction must be simple and expressed by a chemical equation.
2.The reaction must proceed to complete rapidly.
3. The reaction must proceed in a stoichiometric manner.
4.A suitable end point detecting substance (indicator or electrodes)must be available.
5.There must be an alternation in some physical and chemical property of the solution at
the end point.
6. The solutions are stable at experimental conditions.
1.2 TERMS USED IN VOLUMETRIC ANALYSIS:
1. Titrate:The substances to be determined is termed as Titrate.
2.Titrant or Analyte:The substance of known concentration is termed asTitrant.
3. Titration:The process of determinig the volume is termed as Titration.
4. End point:The point at which the reaction is just complete is called end point.
5.Indicator:The substance used to detect the endpoint by sharp colour change is called
indicator. 6.Solution:The homogeneous mixture of two or more compounds is called
solution.
7.Solvent:The major component of solution is called solvent.
8.Solute:The minor component of solution is called solute.
9. Concentration or strength:The amount of solute present in unit volume of solution is
called concentration.
10.Concentrated solution:The solution containing relatively more quantity of solute is called
concentrated solution.
11.Dilutedsolution:The solution contain relatively small quantity of solute is called diluted solution.
12.Standard solution:The solution of known concentration is called standard solution.
13.Standardisation:The determination of concentration of solution is called standardisation.
14.Primary standard:A Standard solution obtained by dissolving a definite weight of
substance having known purity is called primary standard.
Ex:Anhydrous Sodium Carbonate,Potassium dichromate,Sodium Chloride etc.
15.Secondary standard:A secondary standard is a solution which contain exactly known
amount of the substance in unit volume of the solution and concentration is determined
by titrating against a primary standard.
Ex:Sodium Hydroxide,Hydrochloric acid etc.
16.Molarity:The number of moles of solute present in one litre of solution is called Molarity.
17.Normality:The number of gram equivalents of solute present in one litre of solution is
called Normality.
18.Acid:A substance which gives Ht ions in aqueous solution is called acid.
19.Base:A substance which gives OH-ions in aqueous solution is called base.
20.Neutralisation:The reaction between acid and base to form salt and water is called
neutralisation. 21.pH:The negative logarithm of hydrogen ion concentration is called pH.
22.Buffer solution:A solution which resists the change in pH value on dilution or on addition
of small amount strong acid or strong base is called Buffer solution.
Experlment-1
 3
CLASSIFICATION OF TITRIMETRIC REACTION
1.3
Tirimetric reactions are Classified into Four Types:
1
AdBse Tfitats or Netralistin rthA
f lie idi e y .
acid i l
e ad hyt
The titration of free acids or those formed from salts of weak base by hydrolysis with a siandard
base is called

Theabove iration involves reaction beiwenH'and Olf ions to fom waur (oeuralizton)
The following indicators are used as acid base indicators

S.No. Name of Colour in acid Colour in pH range

indicator basic medium
medium
1. Methyl orange Pink or red Yellow 3.0-4.4
2. Phenolphthalei Colourless Pink 8.3-10
n
3. Litmus Red Blue
4. Methyl red Red Yellow 4.2-6.3
5. Thymol blue Yellow Blue 1.2-2.8

2. Complexometric titration:
The titration involving formation of stable complexes by using Chelating agent is
called complexometric titration.
The complexating agent forms coordinate bond with metal ions.The widely used chelaing
agent is disodium salt of EDTA.The indicator is Eriochrome Black-T or Solochrome Black-T.

3. Precipitation Titration;
Titration in which precipitation is formed is called precipitation Titration
A titration in which standard AgNO.is used as titrant is called Argentometric titration

4.Oxidation-Reduction Titration or Redox Titration

A reaction which involves simultaneous oxidation and reduction is redox reaction.Titratior
is carried out on the basis of redox reaction is called Redox Titration
Ex:1.Titration between KMnO₄and Oxalic acid (H₂C₂O₄).KMnO,is self indicator
2,Titration between K.Cr,O,and FeSOa.Potassium ferricyanide is a indicator.
Experlment-1
 aborator Manual in Chemistr
y

1.4 APPARATUS USED IN VOLUMETRIC ANALYSIS :

1, Volumetric lask:
This is a rowd hat botomed ask with a iog nck fited wvih glas stoprn d
prcrare standard sotution.A line marked on the neek,which indicntes the volume of ask.1000ml
500ml,250ml,100ml flasks are used in the laboratory.

Volumetric Flask Preparation Oi

or Standard Solution
Standard Flask

Fig.1

2. Burette:
Burette is long graduated glass tube provided with glass tap at the lower end.It is used
to deliver the solution into conical flask during titration.Generally 50ml.burette graduated up to
0.1 ml,is used in the laboratory.

To Avold Parallox Error Burette During Titration

Glass
Cock Type
Stopper
Burette Burette

Flg.2

Experlment-1
Familirization of Methods for Volumetric Titrimetric Analysis 5

3. Pipette:

Pipette is long narrow glass tube tapering to a fine nozzle at lower endand provided with
bulb in the middle.Aline marked to indicate the volume of pipette.50ml,25ml,20ml,10ml,5ml
pipetts are used in laboratory.

Pipette Correct Way Of Using Pipette Transferring a Solution

Into a Conical Flask

Fig.3

4. Conical flask:

It is a conical shaped flat bottom flask used to take the pipette out solution in the
titration. 250ml,100ml,50ml flsks are used in the laboratory.

5. Glazed tile:

It is a porcelain tile placed under conical flask to identify the correct end point by observing
the colour change

6. Burrette stand:

It is wooden or iron stand used to fix the burette to facilitate the easy titration.

Methods used to Express concentration:

1.Molarity:The number of moles of solute present in I liter of solution is called Molarity.

Experlment-1
 Laboratory Manual in Chemistry
6

2.Normality:The number of gram equivalents present in 1 liter of solution is called

Normality.

3.Weight percentage (W/V):The weight of solute present in 100 ml of solution is called

Weight percentage.

Signature of the Student '

VIVA-VOCE QUESTION

1. What is Titration ?
Ans:The process of addition of one solution from burrette into another solution in the
conical flask is called Titration.
2. What is End point?
Ans:The point at which the neutralization just completed is called End point.
3. What is Indicator ?
Ans:The chemical compound added to conical flask to determine end point by change in
colour is called End point.
4. Name the different types of Titrations ?
Ans:Acid -base titrations,precipitation titration,redox titration,complexometric titration etc.
5. Which indicator is used in Complexometric Titration ?
Ans:Eriochrome balck -T.
6. What is Redox Titration ?
Ans:The titration involving oxidiation-reducation reaction by oxidizing agent and reducing
agent is called Redox Titration.
7. In which type of Titration Self indicators are observed ?
Ans:In complexometric titration of KMnO.with FeSO,KMnO₄ is act as self
indicator. 8. What is pH ?
Ans:Negative logarithm of hydrogen ion concentrations is called pH.
9. Gie pl for Redox Titration.
Ans:Titration between Potassium Permanganate and Oxalic acid.
Experlment-1
 Dluated Solutions

Preparation of Standard Sodium Carbonate

Sohution (Na,CO₃and Making DifrentEsrsim
D;huated Solitions

EXPERIMENT NO.:2
DAT

AlM:

To prepare 250 ml.of 0.05MNa,CO;solution.

APPARATUS;

Physical halance (Analytical balance).Weighing bor,Weighing buttle,Standard tlast (250mll)、

Glass funnel,Wash bottle and pipette.

CHEMICALS;

Anhydrous Sodium Carbonate,Distilled water.

PRINCIPLE:

The solution of known concentration is called standard solution.The concentration is erpressed

in Molarity.

W=0.05×106×4

=1.325g.

1.325g of anhydrous Na₂COs is dissolved in water and makeup to one litre in volumetric
tlask gives 0.05M solution.

Formula:

W=weight of substance.

V=Volume of solution.
Experiment-2
8 Laboratory Manualin Chemlstry

PROCEDURE:
1.About 1.4g of anhydrous Sodium Carbonate is weighed using analytical balance.
2.Weight the substance in weighing bottle (W₁g.)
3.Transfer the substance from weighing bottle into standard flask with the help of funnel.
4.Weigh the weight of empty bottle (W₂g)
5.The substance in the funnel is washed with distilled water and flask is shaken till the
compound is soluble.Then the solution is made up to the mark.
6.Stopper the bottle and solution is thoroughly shaken to form uniform solution.

OBSERVATIONS AND CALCULATION:

Weight of bottle and substance =W₁g B.32S

Weight of empty bottle S.02
=W₂g S

Weight of substance =W₁g-W₂g. ,?

MOLARITY OF SOLUTION:

=…b M.
RESULT:

The Molarity of solution=O:.HqM.

PREPARATION OF DIFFERENT DILUATED SOLUTIONS:
1. Preparation of 100ml of 0.1MNa₂CO₃solution:It is prepared by disolving 1.06 grams
of Na₂CO₃in 100 ml of solution.
2. Preparation of 500ml of 0.1MNa₂CO₃solution:It is prepared by disolving 5.3 grams
of Na₂CO₃in 500 ml of solution.
3. Preparation of 1000ml of 0.05MNa₂CO₃solution:It is prepared by disolving 5.3 grams
of Na₂CO₃in 1000 ml of solution.

Signature of the Signature of tle cturer

Experiment-2
 Preparation of (Na₂CO₃)&Making Different Diluated solution;

VIVA-VOCE QUESTION
1. What is Solution ?
Ans:The homogeneous mixture of two or more compounds is called solution.

2. What is standard Solution ?

Ans:A solution of known concentration is called standard solution.

3. What is Molarity ?
Ans:The number of moles of solute present in one litre of solution is called Molarity.

4. Mention the units of Molarity ?

Ans:Moles/litre

5. What is the GMW of Na₂CO₃?

Ans: 106.(23×2+12+16×3=106)
6. What happens when the solute is Dissolved in Water ?

Ans:The ions formed gets hydrated in solution.

7. Na₂CO₃Solution is Primary or Secondary ?

Ans:Primary standard.

8. 10.6g of Na₂CO₃is dislved in 100ml solution(solution-A)and 106g is dissolved in

1000ml solution(Solution-B).Which one is More Concentrated.
Ans:Both solutions have same concentration because molarity in both the cases is same.

9. What is Molar Solution ?

Ans:A solution containing one mole of solute or one GMW of solute in one litre of solution is
called molar solution.
10. What is Normality ?

Ans:The number of gram equivalents of solute present in one litre of solution is called Normality.

(.

Experiment-2
N 6 A

l 2 1

2 2 )

3 2 l

4 |

S l
 Estimation of HCl using Standar ₂co,Solutíon

Estimation of HCl using Standard

NA₂CO₃Solution

EXPERIMENT NO.:3 DATE:

AIM:

To find the Molarity and to estimate the Hydrochloric acid present in llitre of solution by
using 0.05M Sodium Carbonate (Na₂CO₃)solution.
APPARATUS;

Burette,Pippet,Conical flask,beakers,Burett stand,Glazed tile and wash bottle.

CHEMICALS:

Hydrochloric acid,
Standard Sodium carbonate solution (0.05M),

Distilled water
Methyl orange indicator.

PRINCIPLE;

Na₂CO₃is week base and HCl is strong acid.The reaction between acid and base to form
salt and water is called Neutralisation.Hydrochloric acid reacts with Sodium carbonate solution to
form NaCl,Water and Carbon dioxide

Na₂CO₃+2HCl→2NaCl+H₂O+CO₂
1 mole of Na₂CO₃=2 moles of HCl
FORMULA:

1.

HCI Solution :

M₁=Molarity of HCl

V₁=Volume of HCl

n₁=No.of moles of HCl

Experlment-3
 taberatory Manual in Chemistry

Na₂CO,solution:

M.=Molariy ef Na,C0;

V:=Votume ef Na,CO;

n:=Na ef mols oi Na.CO;

2.Amumt of HCl prsent in I litre of solution =Molanity of HClx Molecular Weight of
HC(36.5)
PROCEDURE;

1.he burete is rinsed with tap water,with distilled water and finally with Hydrchloric
acid Buret is filled with HCl and reading is adjusted to "O° .
2.A 20ml pipete is rinsed with tap water,with distilled water and finally with given Sodium
Carmate olution and solution is transferred into a clean cmical-flask.
3.Add lar 2 dops of Methyl orange indicator.The solation tums to Fellow.
4.Place the emical flask under the burette on the porelain tile.Add HC!drop by drop
from burene with eonstam shaking untl colour changes to pink.
5.Repeat the titratiom until two concordam reading are obtained The values are entered in the
tahular form.

Observstions and Calenlstions:

Burete :Hyirochlarie acid

Pqeme :Sandrd Na₂CO;solution.

End peim:Yellow to pink
SNo Voleme of Barette Volame of HC
Na,CO₃ readings(ml) run
solution Initisl Finsl down(V₁)ml
(V₂)ml
1、 20ml

2. 20ml

3 20l

4 20ml

5. 20ml

Experiment-3
Estimation of Hc!using standard Na,CO,Solutian

CALCULATIONS:

HCl solution

M₁:Molarity of HCl=?

V₁:Volume of HC1=12

n₁:No.of moles of HCl=2.

Na₂CO₃Solution:
M₂:Molarity of Na₂CO₃=0.05M

V₂:Volume of Na₂CO₃=20ml
n₂:No.of moles of Na₂CO₃=1

aywtc. 0 ·0 ×20x-,云、0-166
Amount of HCl present in l litre soltion

=Molarity of HC1(M)×Gram molecular weight of HCl(36.5)

=M₁ ×36.5 =0·166X36·5
=6..053.gl
RESULT:

1.Molarity of HCl solution =a.l66.m

2.The amunt of HC/present in I lire solution=6:0S3gL

Signature of the Studerit

Experiment-3
14 Laboratory Manualin Chemistry

VIVA-VOCE QUESTION

1. How many moles of HCl is required to react with one mole of Na₂CO₃?

Ans; 2 moles

2. Sodium carbonate solution is basic in nature.Why?

Ans:Sodium carbonate produces hydroxyl ions by reacts with water and it is a basic in nature.

3. Methyl orange indicator turns to pink at end point.Why ?

Ans:As the titration proceeds the medium changes from basic to neutral and then to
acidic.In acidic medium methyl orange indicator gives pink colour.
4. What is the relation between molarity of the solution and weight of the solute present
in the solution ?
Ans:Weight of the solute present in solution =Molarity of the solution ×gram molecular weight
of the solution.

5. What is standard solution ?

Ans:A solution of known concentration is called standard solution.

DESCRIPT/ON G A f

2 0

2 l 0

3 2 | O

U 2 l

5 (
1 ○

Experiment-3
 Estimation Hydroxide Using Standard HCl Solution

Estimation of Sodium Hydroxide

Using Standard HCl Solution

EXPERIMENT NO.:4
DA

AIM:

To find the Molariy and to estimate the amount of Sodium Hydroxide present in 1 litre of
solution by using 0.05M HCl solution.

APPARATUS:

Burette,Pipette,Conical flask,beakers,Burette stand,Glazed tile and wash bottle.

CHEMICALS ;

Sodium Hydroxide:
Standard Hydrochloric acid (0.05M),

Distilled water
Methyl orange indicator.

PRINCIPLE:

NaOH is strong base and HCl is strong acid.The reaction between acid and base to form salt
and water is called Neutralisation.Hydrochloric acid reacts with Sodium Hydroxide solution to form
NaCl and water.

NaOH+HCl →NaCl+H₂O

1 mole NaOH =1 mole HCl

FORMULAE:

1.

HCl Solution ;

M₁=Molarity of HCl

V₁=Volume of HCl

n₁=No.of moles of HC!

Experiment-4
 CAICULATIONS:

HCl volutim:

M₂:Molariy cfHCl=00SM
v,:ime cfHa=14
m₁:Na.df moies cf HCI=1
NzOH vlxtim

M₂:Mrsy cf NzOH =?

V₂: tine cf NaOH =20ml

二 ：Na.dfmcls cf NaOH=1

vmw keun pan ml are dt scizin

=Molariy ofNtOHx Molselnr War ofNa0H(40

=M×40

=⊥4 L
RESULT:

1.Miarny ofkaOH=L.O3
2.Acorn of NaOH prser in 1 Iire of sciri =

Segxture of the Sulen

atert the Lcttrer

Eagtrimtnt-4
Estimation of Sodium Hydroxide Using standsrd hcl Solution 17
CALCULATIONS:

HClsolution:

М,: Molarity ofHC/ = 0.05м

У: Уoите оГнС е ЦЧ
n, : No. 6f moles of HC/ = 1
NaOH solution

М, : Molarity of NaOH = ?
V, : Vlume of NaOH = 20ml

n, : No. of moles of Na0H =1

»0-05 х(Ч O·
Эо
уШ
С
2
20 LD O

Моагу оГМаОН-ОгоЗМ 1 V -о

Amount of NaOH present in [litre of solution

M oarity оГМаОН х Мо1есшаг VетдШ оГМаОН (40)
= M, x 40
е.I:.Ч......уи
RESUIТ :

2. Amount of NaOH present in 1 ire ofsoluton = 1:.Ч.....лЛ.

Signature ol the Student Signature of the Lecturer

Ехоептепк-А
 Laberatery Manusl in Chemlstry

N.x2R sahsm:
M:*Moarip ef NaOH

V:”Nwume of NaOH

n.*Na dfmls of NaOH

Amut ef NaOH mrent in I lite of solumion =Molarity of NaOHN Molecular Weight of
NaOH(40).

FROCEDURE:
1.Rimse and fill the bureme with standarnd Hydnchloric acid (0.05M)
2.Ppeee an 20ml ef Sdium Hydrmide soluion into a clean anical flask.

3.Aat 2ar 3 dps Mettyl orange indicato.The solution tums to yellow.

4.Tiratt the snlunon with staniand Hydnchlorie acid until the yellow colour changes to
pink mlar.Repeat the atraton until mo amondant reading are ohtained.The values are
entered in the tahular firm

OBSERVATIONS AND CALCULATIONS:

Birete :Sandard Hydnchlarie acid solution (0.05M).

Pipee :Sdum Hydraride solution.

End puimt:Yellow to pink.

SNe Volume of NaOH Burette Yolume of HCl

solutian (V.)ml readings(ml) run
Initial Final down(V,)
mi

1. 20ml 0-0 1y ly
20
2. 20 ml l4 14

3. 20 m

20 ml

20 m!

Experiment-4
Estimation of Sodium Hydroxide Using Standard HC!Solution

CALCULATIONS:

HCl solution;

M₁:Molarity of HC/=0.05M

V₁:wlume ofHc-14
n₁:No.of moles of HCl=l

NaOH solution

M,:Molarity of NaOH=?

V₂:Vlume of NaOH=20ml

n₂:No.of moles of NaQH-1

0·05 xl1X
M-mY 二 , 。

1 X20
Amount of NaOH present in Tlitre of solution

=Molarity ofNaOH×Molecular Weight of NaOH(40)

= M,×40

l:……g L
RESULT;

l.Molarity ofNaOH 0.035

2.Amount of NaOH present in I litre of solution …gL.

Signature of the Student Signature of the Lecturer

Experlment-d
 28

VTVA-VOCE QUESTION

1. Titration between HCl and NzOH is which type ef reaction?

Ans:Netraliztion ractim.

2. What is the moleeular weight of NaOH.

Ams:40(23-16÷1)

3. Whzt is the molar ratio of NzOH and HCl in the titration of HCl and NaOH.

Ans:1:1 rtio.

4. When wdium hydroride pellets zre erpned to ztmnphere becomes watery,Why ?

Ans:NzOHis deliguesoant solid and abssrts moisure from atmosyhere and beoomeswatsry.

5. What is molzrity of 4%NzOH wlution

6. What isthe weirght ofNaOH reguired in one Hitr to

camgleteneutrzlioe0.IMHCIwlatvm?
Ans:4 grams (4 gams NaOH is disvived in one liar to wepre 0.1M NeOH.

1 1

2 1

3 2 { b
4 2 1
1
2 /
Laperiment·4
 Standard NaOH Solution
19

Estimation of H,SO,using
Standard NaOH Solution

EXPERIMENT NO
DATE
AlM:

To find the Molarity and to estimate the Sulphuric acid present in llitre of solution by
using 0.05M Sodium Hydroxide solution.

APPARATUS:
Burette,Pipette,Conical flask,beakers,Burette stand,Glazed tile and wash bottle.

CHEMICALS

Sulphuric acid
Standard Sodium hydroxide solution (0.05M),

Distilled water
Methyl orange indicator.

PRINCIPLE:
NaOH is strong base and H,SO₄is strong acid.The reaction between acid and base to form salt
and water is called Neutralisation.Sulphuric acid reacts with Sodium hydroxide solution to form
Na₂SO₄and Water.
H₂SO₄+2NaOH→Na₂SO₄+2H₂O
2 mole of NaOH=1 moles of H₂SO₄
FORMULA:

H₂SO₄Solufion;
M₁ Molarity ofH₂SO.
V₁=Volume ofH₂SO₄

n₁No.of moles of H₂SO₄

Experlment-5
…
 Laboratory Manual In
NaOH solution :
M, 0·IM)
Molarity of NaOH

V₂ Volume of NaOH 2 0
n₂ No.of moles of NaOH
2.Amount of H₂SO₄present in d litre of solution Molarity of H₂SO₄×Molecular
Weight ofH₂SO₄(9S)
PROCEDURE:
1.The burette is rinsed with tap water,with distilled water and finally with sulphuric acid.
Burett is filled with H₂SO,and reading is adjusted to "O".
2.A20ml pipette is rinsed with tap water,with distilled water and finally with given Sodium
hydroxide solution and solution is transferred into a clean conical flask.
3.Add lor 2 drops of Methyl orange indicator.The solution turns to Yellow.
4.Place the conical flask under the burette on the porcelain tile.Add H₂SO₄drop by
drop from burette with constant shaking until colour changes to pink.
5.Repeat the titration until two concordant reading are obtained.The values are entered in
the tabular form
Observations and Calculations:
Burette :Sulphuric acid.
Pipette :Standard NaOH solution.
End point:Yellow to pink.

S.No Volume of Burette Volume of

readings(ml)
NaOH H,SC
solation Initial Final down(V₁)mt
(V₂)ml
1. 20 ml C
2. 20 ml 18

3 20 ml

4 20 ml

5. 20 ml

Experiment-5
нитапоКъЕн,бо,лкмттканкон

CALCULATIONS:

lClsolulon

M,: MoariyofH,S0,"?0 -[М)

У Уиите оГН,5О,-ЧА-
n, : No. of moles of H,S0, " 1.1
МaОН Solulon

М, : Molarity of NaOH = 0.05M

V, :VoIите оГ МаОН е 2ОтЦ

n, : No. of moles of NaOH = 2

МоагПу оГН,8О,, 0 ' S х2-0 х ]

2x4
Amount of H,SO, present in 1 litre solution

Molarity of H,S0, (M,) x Gram molecular weight of H,50, (98)

= M, x 98
6..Чb(...;/I
RESUЕТ;
1. Molarity ot H,S0, solution = 1:.&.Ч...
2. The amount of H,SO, present in 1 liresolution =&...4.88.g/ L.

Slgnature of the Student

Expermenr.5
 22 ДаЬога1огу МапиаИп Смтр

УІУА-УОСЕ
ОИЕБТЮМ
1Н оw maпу molesofNaOHls required io react wih one mole ol H,50,?
A ns: 2 moles,

2. Vhatlsthe basiciy of H,S0, whatls the reason ?

Ans: Basicity of H,S0,is 2. Because it contains two replacable hydrogen atoms.

3. Methyl orangelndlcator turns to pink at end polnt. Why ?

Ans: As lhe titration proceeds the medium changes from basic to neutral and then to acidc.
l acidic medium methyl orange indicator gives pink colour.

4. Which chemical is called king of chemicals.

Ans: H,504

5. H,SO,is used as dehydrating agent in organic compounds. Why ?

Ans: H,S0, shows strong affinity to water and removes water. Неnсе it is used as
dehydratnр agent.

A P

1 1 O

1 ⊙

) 〇

Expelment-5
Estimation of Mohr's Snltbv Using Standord KMno,Solutfon 23

Estimation of Mohr's Sah

by Using Standard KMnO,Solulion

EXPERIMENT NO.:6
DAT

AIM:

To find the Molarity and to cstimate the amount of Ferrous Ammonium Sulphate (Mohr's
Salt)present in I litre of solution by using 0.02M Polassium Permanganate
(KMnO₄)solution.
APPARATUS:

Burette,Pipette,Conical flask,beakers,Burette stand,Glazed tile and wash bottle.

CHEMICALS:

Standard KMnO₄solution (0.02M),

Mohr's salt solution

Dilute H₂SO₄solution

Distilled water.

PRINCIPLE:

The chemical formula of Mohr's salt is FeSO₄(NH₄)₂SO₄6H₂O.The reaction

between KMnO₄and Mohr's saltis Redox reaction(Reduction-Oxidation).KMnOq isstrong
oxidizing agent and Mohr's saltis reducing agent.KMnO oxidises Ferrous sulphate present in
Mohr's salt.KMnO₄ is act as self indicator and no external indicator is required.
2KMnO₄+10FeSO₄+8H₂SO₄→K₂SO₄+2MnSO₄+5 Fe₂(SO₄)₃+8H₂O
Or

5F2++MnO₄F+8 H⁴→5 Fe³⁴+Mn²⁴+4H₂O

2 moles of KMnO₄=10 moles of Mohr's salt

1 mole of KMnO₄=5 moles of Mohr's salt

PROCEDURE:

1.Burete is cleaned with distilled water and filed with standard

KMnO,solution.Initial reading is adjusted to '0'.
Experiment-6 {A.P}
 Laboratory Manua n Chemis

2.Pipette out 20ml of Mohr's salt solution into a clean conical flask with a Pippet
3.Add 20ml of dilute Sulphuric acid to conical flask.No indicator is required.
4.Titrate the Mohr's salt solution against Potassium permanganate solution until
a solution attains permanent pink colour.
5.Repeat the titration to get two concordant reading.The values are entered in the tabu.
form.
OBSERVATIONS AND CALCULATIONS:
Burette :KMnO₄solution (0.02 M)
Pipette :Mohr's salt solution
End point :Appearance of pink colour

S.No Volame of Burette Volume of

Mohr's readings(ml) KMnO₄ run
salt Initial Final down(V₂)ml
solution(V₁)ml

1. 20 ml
z

20 ml

3 20 ml

4 20 ml

5. 20 ml

CALCULATIONS:
Mohr'salt solution
M₁: Molarity of Mohr's salt solution=?

V₁:Volume of Mohr's salt solution =20ml

n₁:No.of moles of Mohr's salt =10.
KMnO₄SOLUTION:
M₂:Molarity of KMnO₄solution =0.02M
V₂:Volume of KMnO₄solution =20ml
n₂ :No.of moles of KMnO₄=2
Experiment-6
 Estimation of Mohr's Salt by Using Standatd KMnO.Solution 25

MOLARITY OF MOHR'S SALT:

=0:L.m
Amount of Mohr's salt present in one litre of solution =M₁×392
3·92
二 …………g/L

RESULT:

1.Molarity of Moh's salt solution =Q:.m

3.10(
2.The amount Mohr's salt present fn I litre solution …

of the Leetur
Signature
Signature of the Student

(A.P)
Experiment
 26 laboratory Manual in Cheml

VIVA-VOCE QUESTION
1. What is Mohr's Salt.

Ans:Ferrous ammonium sulphate is called Mohr's sealt.

2. Which type of titration involved in the estimation of mohr's salt.

Ans: Redox titration.

3. Which one is oridant and reductant in estimation of mohr's salt.

Ans: Retuctam-KMnO,Oxidant FeSO

4. No indicator used in the titration between mohr's salt and potassium permangate solution.
Why?

Ans:Mn²-formed in the reaction is act as self indicator and no external indicator is necessary.

5. What is the change in oridation number of KMnO,in redor reaction.

Ans: The oxidation number of Mn changes from+7 to +2.So change in oxidation number is +5.

5.N DESCRIPT1ON A
0
1 |

2 1 O

] 0

4 1 ○

5 ) 〇

Experlment-6
 Determination of Aeldity cf Watet Somple
27

EXPERIMENT NO.7: D
AIM:

To determine the partial and total acidity of given water sample by using 0.02 N
Sodium Hydroxide solution.

APPARATUS:

Burette,Pipette,Conical flask,beakers,Burette stand,Glazed tile and wash bottle.

CHEMICALS:
Standard Sodium Hydroxide solution (0.02N).

Sample water.

Distilled water.
Methyl orange indicator.

Phenolphthalein indicator.
Sodium thiosulphate (Hypo)0.02 N.

PRINCIPLE:
Acidity ofa water sample is a measure of its ability to neuralize bases or to resist change in
ptvalue.Acidity of water is due to presence of mineral acids like H,SO,,HNOsete.and CO,in
the form H₂CO₃ ·
The acidity if water sample is estimated by titrating with 0.02 N NaOH solution by
using Methyl orange and Phenolphthalein indicators.Titration to pH 4.5 with methyl orange
indicator gives partial acidity.Titration to pH 8.4 with phenolphthalein gives total acidiiy.
Acidity is expressed in terms of CaCOs equivalents
FORMULA:
Acidity in water sample

50=Equivalent weight of CaCO₃

Experiment-7
 … ……… … … ……
Laboratory Manual in
A. Methyl orange Acidity (Mineral acidity)or (Partial acidiyy):
1. Rinse and fill the burette with standard NaOH solution
2.Pipette out 20ml of sample water into conical llask.
3.Add I or 2 drops of Hypo and 1 or 2 drops Phenolphthalein indicator to the sample.

4.Titrate the sample against 0.02N NaOH until pink colour changes to yellow.
5.Repeat the titration until two concordant reading are obtained.The values are entered inthe
tabular form.
OBSERVATIONS AND CALCULATIONS:
Burette : Standard NaOH solution(0.02N)
Pipette :20 ml sample water
End point :Pink /red to yellow.

S.No Volume of Burette Volume of

sample readings(ml) NaOH run
water (ml) Initial Final down (V₂)ml

0·0
1. 20 ml 6-4
2. 20 ml 6·4 12.08

3. 20 ml

4. 20 ml

5. 20 ml

CALCULATIONS:
Acidity of water sample in terms of CaCO₃equivalents

3:2.0.ppm
Mineral Acidiy=… 32.0
Experiment-7
 Oeterminatien of Acldity of Water Sample 29

B. Phenolphthalein Acidiiy(Total acidity):

1. Rinse and fill the burette with standard NaOH solution
2.Pipette out 20ml of sample water into a conical flask.
3.Add l or 2 drops Phenolphthalein indicator to the sample.
4.Titrate the sample against 0.02N NaOH until pink colour appears.
5.Repeat the titration until two concordant reading are obtained.The values are
entered in the tabular form.
OBSERVATIONS AND CALCULATIONS:
Burette : Standard NaOH solution (0.02N).
Pipette :20 ml sample water.
End point:Colourless to pink /red.

S.No Volume of Burette Volume of

sample readings(ml NaOH run
water(ml) Initial Final down(V)ml

1. 20 ml Q

2. 20 ml

3. 20 ml

4. 20 ml

5. 20 m

CALCULATIONS:
Acidity of water sample in terms of CaCOs equivalents

=.2.?5……ppm
Phenolphthalein Acidity=…?.?.3……ppm
Experiment-7
* …… ……
 Laboratory Manual In Chemlstry
3.0

IRESULT:

1.Total acidity

2.Mineral acidity =

3.Carbonate acidity m Total acidity -Mineral acidity

1 D*ACR!P) 67 A P

2 2 ( 〇

2 Z 1 C
1lo
S ignature of the Signature of the
Student 4 2 ( Lecturer

VIVA- QE TO
VOCE US IN

1. What is Acidity ?

Ans:The measure of capacity to neutralize bases is called Acidity.

3. Mention the indicators used to determine acidity of water sample.

Ans:Methyle orange and phenolphthelin.

4.Why hypo solution is added to sample water in the determination of acidity ?

Ans:Hypo solution is added to water sample to remove residual chlorides.

5. What are the units of Acidity ?

Ans:The acidity of water is expressed in terms of CaCO;equivalents in PPM.(Mg per liter).

6.Wat is equivalent weight of CaCO;

(A.9 Experiment.7
 paterminaton of Alkalinity of Water Somple

Delermination of Alkalinily of
Water Sample

EXPERIMENT NO.:8
DAT

AIM :

To determine the partial and total alkalinity of water sample by using 0.02 N H₂SO₄solution.

APPARATUS:

Burette,Pipette Conical flask,beakers,Burette stand,Glased tile and wash bottle.

CHEMICALS:

Standard Sulphuric acid solution (0.02N)

Sample water

Distilled water

Methyl orange indicator

Phenolphthalein indicator.

PRINCIPLE:

Alkalinity of a water is a measure of its ability to neutralize acids or to resist change in

PH value.Alkalinity of water is due to presence of soluble
bicarbonates,carbonates,hydroxides, phosphates and borates.Bicarbonates are most common
source of alkalinity.

Alkalinity is determined by titrating water sample with 0.02 N H,SO,solution.Titration to

pH 8.3 with phenolphthalein indicator gives partial alkalinity.Titration to pH 4.5 with Methyl
orange indicator gives total alkalinity.

Alkalinity is expressed in terms of CaCOs equivalents in ppm.

FORMULA:

Alkalinity in water sample

50 =Equivalent weight of CaCO₃

Experiment-8
32 Laboratory Manual in Chemlstry

4. Phenolphthalcin Alkalimio (Parial.Alkalinio):

1.Rinse and fill the burette with 0.02 N standard Sulphurie acid solution.
2.Pipette out 20ml of sample water into a conical dlask.
3.Add I w 2 drops Phenolphthalein indicator to the sample.
4.If pink colur apyears (alkalmity is present)titrate the sample against 0.02N Sulphurie
aeid until pink colour diappears.
5.Repeat the titration until two concordant reading are obtained.The values are entered in the
tabular form.
OBSERVATIONS AND CAICULATIONS:
Burette :Standard H,SOsolution(0.02N)
Pipxtte :20 ml sample water
End point:pink /red to colourless

S.No Volume of sample Burette Volume of

readings(ml) H₂SO₄run
water(ml)
Initial Final down(V₁)ml
1. 20 ml O 1 |

2. 20 ml 2
—

3. 20 ml

4. 20 ml

5. 20 ml

CALCULATIONS:

Partial Alkalinity of water sample in terms of CaCO₃equivalents

.5.0…ppm
Phenolphthalein Alkalinity=…5……ppm.
(or)
Partial alkalinity
(A.P)
Experiment-8
 Oetutminalon of Alkalinlty of Woter Somple 19

n. Mtethyt Orange Alkalinlty(or)Total Alkalinity):

1.Rinse and fill the burette with 0.02 N sulphurie acid solution.
2.Pipette out 20 ml of sample water into a clean conical flask,

3.Add for 2 drops of Methyl orange indicator to the sample water.

4.If yellow colour appears,titrate the same against 0.02 N H,SO,until pink colour appears
5.Repeat the titration until two concordant readings are obtained.The values are entered in
the tabular form.

OBSERVATIONS AND CALCULATIONS:

Burette :Standard H₂SO₄solution (0.02N)

Pipette :20 ml sample water
End point :yellow to pink /red.

S.No Volume of Burette Volume of

sample readings(ml) H,SO,run
water(ml) Initial Final down(V₁)ml

1. 20 ml
0
2. 20 ml

3. 20 ml

4. 20 ml

5. 20 ml

CALCULATIONS:

Total Alkalinity of water sample interms of CaCOs equivalent

… …ppm

Methyl orange Alkalinity (m)total alkaliniy =C2 .Ppm

Experiment (A.P)
 Laboratory Munual in Chemistry
34

RESULT:
1.Phenolphthalein alkalinity (partial alkalinity)in terms ofCaCO₃equi ·Pp
2.Methyl orange altalinity (Total alkalinity)interms of CaCOg cquiva .pp

Signature of the Student

VIVA-VOCE QUESTION

1. What is Alkalinity ?
Ans:The measure of capacity to neutralize acids is called Alkalinity.
2. What is cause for Alkalinity ?
Ans:The presence of carbonates,bicarbonates and hydroxyl ions causes alkalinity to the water.
3. Which indicator is used to determine alkalinity caused by hydroxyl ions.
Ans:Phenolphthalein.
4. Which acid is used to Determine Alkalinity ?
Ans:Sulphuric acid (0.02N)
5. What is the Equivalent Weight of CaCO₃and why it is included in the formula used to
calculate alkalinity of water sample
Ans:Equivalent weight of CaCOs is 50.It is included in the formula as alkalinity is expressed in
terms of CaCO;equivalents

OESCRIPT1ON Gn A P

7 !

2 0
4 0

Expel imènt
l
B
 Determination
o Standard EDTA Solution

Determination of Total Hardness of Water

Sample using Standard EDTA Solution

EXPERIMENT NO.:9 DAT

AIM:

To determine the total hardness of water sample by EDTA method.

APPARATUS:
Burette,Pipette,Conical flask,beakers,Burette stand,Glazed tile and wash bottle.

CHEMICALS ;

EDTA solution.

Standard calcium chloride solution (0.02 N)

Eriochrome black -T indicator

Ammonia buffer (pH =10)
Water sample

PRINCIPLE:

Hardness of water is caused due to soluble salts of calcium and magnesium

salts.Calcium and magnesium ions are estimated by titrating with standard EDTA solution by
using Erichrome black -T indicator,

It is complexometric titration and involves reaction between eriochrome black -T

and Calcium and Magnesium ions in water sample to form unstable complex(wine red
colour).This complex on titration with EDTA solution forms complex of EDTA with calcium
and magnesium (blue colour).

[Ca+²,Mgt²]+Eriochrome black-T→ [Ca+2,Mg²Eriochrome black-T]complex

[Wine red colour]

[Ca+²,Mg⁴²]+Eriochrome blackT+EDTA→ [Ca+²,Mg²EDTA]complex+Eriochrome black-T

[Blue colour]
Change of wine red colour to sky blue colour is end point.

Experlment-9
 Laboratory Manual in Chemlstry
36
PROCEDURE:
(4) Standardisation of EDTA solurion:
1. Rinse and fill the burette with EDTA solution.
2.20ml of standard CaCt,solution is taken into conical flask with pippette.
3.Add Iml buttler solution and l or 2 drops of Eriochrome black -T indicator.Solution
turns to wine red colour.
4.Titrate the solution till wine red colour changes to blue colour.
5.Repeat the titration untill two concandarant readings obtained.
Observations and Calculations:
Burette :EDTA solution
Conical Flask :20ml Std.CaCl,solution+1 ml Bufter solution.
Indicator Eriochrome black∵T
Endpoint Wine red to Sky blue.

S.No Volume of Burette Volume of EDTA

readings(ml)
Standard in ml (V₂)
CaCl,n ml. Initial Final
(V₁)
1.

2.

5.

CALCULATIONS:
N₁=Normality ofCaCl₂=0.02 N

V₁=Volume of Std.CaCl₂=20ml
N₂=Normality of EDTA=?

V₂*Volume of EDTA =
Experiment-9
Determination of Totol Hardness of Wster Sample wsing Standard IOTA Solution 37

N₁V₁=N₂V₂
N₂”
...................N
Normality of EDTA(N,) ………………N.
(B) Determination of Total Hardness :
1.Rinse and fill the burette with EDTA solution.
2.20ml of sample water is taken into clean conical flask with pippette
3.Add Iml bufier solution (pH=10)and l or 2 drops of Eriochrome black -T indicator.
Solution turns to wine red colour.
4.Titrate the solution till wine red colour changes to blue colour.

5.Repeat the titration untill two concandarant readings obtained.

Observations and Calculations:

Burette :Std.EDTA solution
Conical Flask :20ml water sample+1 ml.Buffer solution(pH =10)

Indicator :Eriochrome black -T

Endpoint
:Wine red to Sky blue.

S.No Volume of water Burette Volume of EDTA

sample readings(ml) in ml (V₂)
in mL(Vs) Initial Final
1.
20 0·Q 63 6-3
2.
#·3
20 63 13、6

5.

Experiment-9
 38 Laboratory Manual in Chemistry

OBSERVATIONS:

N₂=Volume of EDTA
=

6·3
N =Normality of EDTA 0,02
Vs=Volume of Wzter Sample = 20ml.

CALCULATIONS:

Total Hardness of water sample

::Toal hzrdness of waie sample in terms of CaCOs=…3 Ppm(or)mg/L.

RESULT:
Total Hardness of water sample is =
Ppm pmgl.

Signature of the Student Signarure or tne cccureT

Ergeriment3
Betermination ot Total Hardr
3rd EDTA Slution

VIVA-VOCE QUESTION

1. What is Hardness ?

Ans:The property of hard water by which it does not produces lather with soap is called Hardness.

2. What is the cause for hardness of water sample ?

Ans:The presence soluble bicarbonates,chlorides and sulphates of calcium and magnesium are
cause for hardness of water.

3. Why hardness of water is expressed in terms of CaCO₃equivalents ?

Ans:Hardness of water is expressend in terms of CaCO₃equivalents because it is one of

insoluble products formed during removal of hardness and its molecular weight is 100.

4. What is the permissible level of hardness of water in drinking water.

Ans:200 PPM

5. Why buffer solution is added during estimation of hardness of water by EDTA method.

Ans:Estimation of hardness of water by EDTA method is a complexometric titration.To form

stable complex a PH around 9 to 10 is required.Hence ammonia buffer is added
during titration.
6. What is the colour of Eriochrome black -T indicator in water sample.

Ans:Eriochrome black -T gives wine red colour in sample water due to formation of complex
between calcium and magnesium salts and indicator.

7. Which buffer is used in EDTA method.

Ans:A mixture of ammonium chloride and ammonium hydroxide of pH 10(basic buffer is used
in EDTA method).

8. Expand EDTA.Write its structure.

Ans:EDTA-Ethylene diamine tetra acetic acid.

CH₂COOH
CH₂COOH

9. Which indicator is used in the EDTA method.

Ans:Eriochrome black -T.

10. What is the other method used to estimate hardness of water.

Ans:Soap solution method.

Experiment-9 (A.P)