Aim: Prepare standard Na2CO3 solution. Standardize the given HCl solution and estimate the amount of Sodium hydroxide (NaOH) in the given solution.Part I : Preparation of standard sodium carbonate (Na2CO3) solution.Part II: Standardization of given HCl solution.Part III: Estimation of NaOH in the given solution( Eq.Wt. of Na2CO3 = 53, Eq.Wt. of HCl = 36.50 and Eq.Wt. of NaOH = 40.)

Part I : Preparation of standard sodium carbonate (Na2CO3) solution.Chemicals : Anhydrous Na2CO3, distilled waterApparatus : Beaker, 100 ml standard measuring flask.

Theory : Normality is defined as the number of grams equivalent weight of solute dissolved in liters of solution. That is,

Thus, 0.53 grams of Na2CO3, is dissolved in distilled water to prepare 100 ml of solution.

Procedure : 0.53 grams of anhydrous Na2CO3 is accurately weighed and dissolved in distilled water suing 100 ml standard measuring flask. This is 100 ml of 0.1 N solution of Na2CO3.

Part II: Standardization of given HCl solution.

Chemicals : Standard 0.1 N solution of Na2CO3, given HCl solution and Methyl orange indicator.Apparatus : Beakers, pipette, burette conical flask etc.Theory : Sodium carbonate is neutralized by HCl and completion of neutralization is detected by

methyl orange indicator. The end point is yellow to pink.

Procedure1) The burette is rinsed and filled with given HCl solution.2) 10 ml of Standard (0.01N) sodium carbonate solution is pipetted into a 100 ml conical flask and

added a 2-3 drops of methyl orange indicator.3) Titrated the above with HCl solution till yellow colour of solution changes to pink.4) The titration is repeated to get three concordant readings.

S. No.

Burette reading (Volume of HCl)

Initial Final Difference

(1)

(2)

(3)

1

Calculation:

N1 = Normality of HCl solution. = ?V1 = Volume of HCl solution. = B.R. =N2 = Normality of Sodium carbonate solution. = 0.1 NV2 = Volume of Sodium carbonate solution. = 10 ml

HCl v/s Na2CO3

N1V1 = N2V2

N1 = N2V2

V1

= 0.1 x 10 B.R.

Normality of HCl solution = ____ N

Part III: Estimation of NaOH in the given solutionChemicals : Standardized HCl solution, given NaOH solution and phenolphthalein indicator.Apparatus : Beakers, pipette, burette conical flask etc.Theory : Sodium hydroxide is neutralized by HCl and completion of neutralization is detected by

phenolphthalein indicator. The end point is colourless to pink.

Procedure1) The burette is rinsed and filled with given Standardized HCl solution.2) 10 ml of given sodium hydroxide solution is pipetted into a 100 ml conical flask and added a 1-2

drops of phenolphthalein indicator.3) Titrated the above with HCl solution till solution changes from colourless to pink.4) The titration is repeated to get three concordant readings.

S. No.

Burette reading (Volume of HCl)

Initial Final Difference

(1)

(2)

(3)

Calculation:

N1 = Normality of NaOH solution. = ?V1 = Volume of NaOH solution. = 10mlN2 = Normality of HCl solution. = x N (calculated as above)V2 = Volume of HCl solution. = __ ml (B.R.)

NaOH v/s HClN1V1 = N2V2

N1 = N2V2

V1

= x X B.R = ____ N 10

Strength of NaOH = Normality X 40 grams / liter

2

Aim: Estimate the amount of NaOH and Na2CO3 in the given mixture using standard HCl solution.

Chemical: Standard (0.1N) HCl solution, Given (NaOH + Na2CO3) mixture solution, phenolphthalein and methyl orange indicator.

Apparatus: Beakers, pipette, burette conical flask etc.Theory: The neutralization of NaOH and Na2CO3 by HCl is indicated by phenolphthalein and methyl

orange indicator. Phenolphthalein indicator show complete neutralization of NaOH and half neutralization of Na2CO3. Methyl orange indicator indicates the remaining half neutralization of Na2CO3. This is illustrated as –First Stage (phenolphthalein is used as indicator)

Second Stage (methyl orange is used as indicator)

Procedure:1) The burette is rinsed and filled with given Standardized HCl solution.2) 10 ml of given (NaOH + Na2CO3) mixture solution is pipetted into a 100 ml conical flask and added

a 1-2 drops of phenolphthalein indicator.3) Titrated the above with HCl solution till solution changes from colourless to pink. The burette

reading is noted as X ml. This indicates complete neutralization of NaOH and half neutralization of Na2CO3.

4) To same solution, 2-3 drops of methyl orange indicator is added. The solution turns yellow.5) The titration is continued (from X ml) till yellow colour changes to pink. The burette reading is noted

as Y ml. This indicates the remaining half neutralization of Na2CO3.6) The titration is repeated to get three concordant readings.

S. No.

Burette reading (Volume of HCl using

phenolphthalein indicator)

Burette reading (Volume of HCl using methyl

orange indicator)(X-Y)

ml2Y ml

Initial FinalDifference

(Xml)Initial Final

Difference (Yml)

(1)

(2)

(3)

Calculation:Estimation of NaOH in the given mixture:

N1 = Normality of NaOH solution. = ?V1 = Volume of NaOH solution. = 10mlN2 = Normality of HCl solution. = 0.1 N V2 = Volume of HCl solution. = __ ml (X-Y ml)

NaOH v/s HClN1V1 = N2V2

N1 = N2V2

V1

Normality of NaOH in mixture solution = 0.1 X (X-Y ml) = ____ N 10

Strength of NaOH in given mixture solution = Normality X 40 grams/liter

3

Estimation of Na2CO3 in the given mixture:N1 = Normality of Na2CO3 solution. = ?V1 = Volume of Na2CO3 solution. = 10mlN2 = Normality of HCl solution. = 0.1 N V2 = Volume of HCl solution. = __ ml (2Y ml)

NaOH v/s HClN1V1 = N2V2

N1 = N2V2

V1

Normality of Na2CO3 in mixture solution = 0.1 X ( 2Y ml) = ____ N 10

Strength of Na2CO3 in given mixture solution = Normality X 53 grams/liter

4

Aim: Standardize the given sodium thiosulfate solution using standard iodine solution and estimate the amount of Na2S2O3 in the given solution.Theory: Sodium thiosulphate is oxidized by iodine giving sodium iodide and sodium tetrathionate.

Starch solution gives an intense blue colour in presence of traces of iodine. Hence, titration of sodium thiosulfate solution against I2 solution is carried out by using freshly prepared starch solution. The change of colour of the solution from blue to colourless is the end point of reaction.Chemicals: Sodium thiosulfate, Iodine, Potassium iodide and Starch solution. Apparatus: Burette, Pipette, Conical flask, Beakers, Etc. Procedure :

1) The burette is rinsed and filled with Sodium thiosulfate solution.2) 10ml of standard iodine solution is pipetted into 100ml conical flask.3) Sodium thiosulfate solution is run down gradually from the burette into conical flask till the solution

attains faint yellow colour.4) 2ml of freshly prepared starch solution is added to the above solution and titration is continued till

the colour of solution changes from blue to colourless.5) The titration is repeated to get three concordant readings.

S. No.

Burette reading (Volume of Sodium Thiosulfate)

Initial Final Difference

(1)

(2)

(3)

Calculation:

N1 = Normality of Sodium thiosulfate solution. = ?V1 = Volume of Sodium thiosulfate solution. = N2 = Normality of standard iodine solution. = 0.1 NV2 = Volume of standard iodine solution. = 10 ml

N1V1 = N2V2

N1 = N2V2

V1

= 0.1 x 10 B.R.

=

Strength of Sodium thiosulfate solution = N1 X equivalent weigt of Na2S2O3

= N1 X 248.2= grams/lit

Result: 1) Normality of Sodium thiosulfate solution =2) Strength of Sodium thiosulfate solution = grams/lit

5

Aim: Estimate the amount of Cu++ in the given solution using standard Na2S2O3 solution. Theory: Copper ions oxidizes iodide to liberate iodine. The liberated iodine is oxidized by Sodium thiosulphate giving sodium iodide and sodium tetrathionate.

Starch solution gives an intense blue colour in presence of traces of iodine. Hence, titration of sodium thiosulfate solution against I2 solution is carried out by using freshly prepared starch solution. The change of colour of the solution from blue to colourless is the end point of reaction.Chemicals: Sodium thiosulfate, Iodine, Potassium iodide and Starch solution. Apparatus: Burette, Pipette, Conical flask, Beakers, Etc. Procedure :

1) The burette is rinsed and filled with Sodium thiosulfate solution.2) 10ml of standard Cu2+ solution is pipetted into 100ml conical flask.3) Sodium carbonate solution is added dropwise till the appearance of a slight turbidity.4) The turbidity is dissolved in dilute acetic acid so as to get a clear light blue solution.5) 10ml of 10% KI solution is added into the flask.6) Sodium thiosulfate solution is run down gradually from the burette into conical flask till the solution

attains faint yellow colour.7) 2ml of freshly prepared starch solution is added to the above solution and titration is continued till

the colour of solution changes from blue to colourless.8) At this stage added 2 ml of ammonium thiocyanate solution and continued the addition of sodium

thiosulphate solution till the blue colour disappears.9) The titration is repeated to get three concordant readings.

S. No.

Burette reading (Volume of Sodium Thiosulfate)

Initial Final Difference

(1)

(2)

(3)

Calculation:

N1 = Normality of standard Sodium thiosulfate solution. = 0.1NV1 = Volume of standard Sodium thiosulfate solution. = B.R.N2 = Normality of Cu2+ solution. = ?V2 = Volume of Cu2+ solution. = 10 ml

N1V1 = N2V2

N2 = N1V1

V2

= 0.1 x B.R 10

Strength of Cu2+solution = N2 X equivalent weigt of Cu2+

= N2 X 63.5= ________ grams/lit

Result: Strength of Cu2+solution = ______ grams/lit

6

Aim: Find out the strength of supplied NaCl solution using standard NaCl and AgNO3 as link solution (Mohr’s method). Part 1: Standardization of AgNO3 solution.Part 2: Estimation of NaCl

Theory: Mohr’s method is used for determination of chloride by titrating with standard solution of silver nitrate in a neutral medium. It is a direct titration method. Potassium chromate (K2CrO4) used as indicator.

At the end point: The excess of Ag+ reacts with the indicator to precipitate as red silver chromate after precipitation of all chlorides as silver chloride.

Chemicals: Sodium chloride, Potassium chromate as indicator and Standard (0.01N AgNO3 solution).

Apparatus: Burette, 10 ml Pipette, 100 ml conical flask, beakers etc.

Part 1: Standardization of AgNO3 solution.

Procedure7) 10 ml of Standard (0.01N) sodium chloride solution is pipetted into a 250 ml stoppered conical flask.8) To the above, added 10 ml distilled water and 1 ml potassium chromate indicator.9) Titrated the above with AgNO3 solution, swirling the liquid constantly, until the red colour formed

by addition of each drop of AgNO3 solution begins to disappear more slowly; this is an indication that most of chloride has been precipitated and that the end point is near.

10) The titration is continued until a faint, but distinct, brick red color is formed and does not disappear on vigorous shaking.

CalculationAgNO3 V/S NaClN1V1 = N2V2

N1 = N2V2

V1 =

Normality of AgNO3 = _______ N

Part 2: Estimation of NaClProcedure

1) 10 ml of Standard (0.01N) sodium chloride solution is pipetted into a 250 ml stoppered conical flask.2) To the above, added 10 ml distilled water and 1 ml potassium chromate indicator.3) Titrated the above with AgNO3 solution, swirling the liquid constantly, until the red colour formed

by addition of each drop of AgNO3 solution begins to disappear more slowly; this is an indication that most of chloride has been precipitated and that the end point is near.

4) The titration is continued until a faint, but distinct, brick red color is formed and does not disappear on vigorous shaking.

CalculationNaCl V/S AgNO3

N1V1 = N2V2

N1 = N2V2

V1

Strength of NaCl = N1 X 58.5 gms / liter.

7

Aim : Standardize the given EDTA solution by using standard Zn2+ solution and estimate the amount of Ca2+ from the given solution.

Standardization of EDTA Solution

Theory: EDTA from complex with Zn(II) and hence can be standardized by with titrating given EDTA solution with known volume of standard Zn(II) solution.

Chemicals : Given EDTA solution, Standard (0.01M) Zn2+ solution, buffer solution,Eriochrome Black T indicator.

Procudure:

1. 10-mL of the standard Zn2+ solution is pipetted into 100-ml conical flasks. 2. To the above, added 10 mL of pH 10 buffer (2/3 test tube) and 15 mL of water (1 test tube).

3. Further, added 2-3 drops of Eriochrome Black T indicator.

4. The above content is titrated immediately with EDTA until the light red solution turns a light sky blue. (Titrations must be performed swiftly (but carefully) because ammonia will evaporate and thus the pH of the solution will change. In general, the faster the titrations are performed the better the results will be)

5. The molarity of the EDTA is calculated from the volume of EDTA used.

EDTA v/s Ca2+

Result: Molarity of EDTA = M1 =

8

Estimation of Ca 2+ Solution

Aim : Estimate the amount of Ca2+ from the given solution.

Theory: EDTA from complex with Ca(II) and hence can be estimated by titrating with standardized EDTA solution with known volume of Ca(II) solution.

Chemicals : Given Ca2+ solution, Standardized (____M) EDTA solution, buffer solution, Eriochrome Black T indicator.

Procudure:

1. 10-mL of the Ca2+ solution is pipetted into 100-ml conical flasks. 2. To the above, added 10 mL of pH 10 buffer (2/3 test tube) and 15 mL of water (1 test tube).

3. Further, added 2-3 drops of Eriochrome Black T indicator.

4. The above content is titrated immediately with standard EDTA until the light red solution turns a light sky blue. (Titrations must be performed swiftly (but carefully) because ammonia will evaporate and thus the pH of the solution will change. In general, the faster the titrations are performed the better the results will be)

5. The molarity of the Ca2+ solution is calculated from the volume of EDTA used.

Ca2+ v/s EDTA

9

Result: Ca2+ present in the given solution = M1 x 40 grams = _______ grams

10