PREPARATION OF STANDARD 0.1 (N) HYDROCHLORIC ACID SOLUTIONS
Transfer using a graduated pipette 4.5 ml of
concentrated hydrochloric acid (HCl) into a 500 ml volumetric flask containing
300 ml of water; Cool and dilute to 500 ml. This will give a solution of
approximately 0.1(N) hydrochloric acid.
STANDARDIZATION:
Pipette out 25 ml of the acid solution to a 250 ml conical flask and add 2 drops of methyl red or methyl orange indicator. Titrate with standard 0.1 (N) sodium hydroxide solutions taken in a burette till the colour becomes faint yellow or orange for methyl red and methyl orange respectively.
Normality of HCl acid solution = Vol. in ml of standard NaOH solution x Normality of NaOH
Vol. in ml of hydrochloric acid solution
PREPRATION OF 2(N) SULFURIC ACID SOLUTION
Take distilled water in a 500 ml glass beaker and slowly add 28 ml concentrated sulfuric acid (H2SO4) with stirring. Store this approximately 2(N) H2SO4 solution in a stoppered reagent bottle.
PREPRATION OF STANDARD 1(N) SULFURIC ACID SOLUTION
Transfer using a graduated pipette 14 ml of
concentrated sulfuric acid (H2SO4) into a 500 ml volumetric flask containing about 200 ml of distilled water. Cool and dilute to
500 ml with distilled water. This is a solution of approximately 1(N) sulfuric
acid.
STANDARDIZATION:
Pipette out 25 ml of the acid solution into a 250 ml conical flask and add 2
drops of methyl red or methyl orange indicator. Titrate with standard 1(N)
sodium hydroxide (NaOH) solution until the colour becomes faint yellow or
orange for methyl red and methyl orange respectively.
Normality of sulfuric acid solution = Vol. in ml of
standard Noah solution x Normality of NaOH
Vol.
in ml of sulfuric acid solution taken.
Buffer solution in chemistry and Types of buffer Solutions
PREPRATION OF STANDARD 0.1 (N) SULFURIC ACID SOLUTIONS
Transfer using a graduated pipette 1.4 ml of
concentrated sulfuric acid H2SO4 into a 500-ml
volumetric flask containing about 200 ml of distilled water. Cool and dilute to
500ml with distilled water. This is a solution of approximately 0.1(N).
Sulfuric acid.
STANDARDIZATION:
Pipette out 25 ml of the acid solution into a 250 ml conical flask and add 2
drops of methyl red or methyl orange indicator. Titrate with standard 0.1 (N)
sodium hydroxide solutions till the colour becomes faint yellow or orange for
methyl red and methyl orange respectively.
Normality of sulfuric acid solution = Vol. in ml of standard NaOH
solution x Normality of NaOH
Vol.
in ml of sulfuric acid solution taken.
PREPARATION OF STANDARD 1(M) Sodium Sulphite (Na2SO3) SOLUTION
Weigh out accurately 31.5 gm of Sodium Sulphite (Na2SO3) and
quantitatively transfer to a 250ml volumetric
flask. Make up the volume up to the mark with distilled
water and shake to make a standard 1 (M) Sodium Sulphite solution.
Keep it in the volumetric flask under
stoppered conditions. This is a standard 1 (M) Sodium
Sulphite solution.
PREPARATION OF 0.1 N OF AQ.KOH SOLUTION
Dissolve 2.8 gms of KOH flakes (potash alkali) in 200 ml of Distilled water in a 500 ml volumetric flask. After complete dissolution make up to mark with
distilled water.
STANDARDIZATION OF KOH SOLUTION:
Make a standard 0.1 N Oxalic Acid solution and take 25ml of this solution with
the help of the pipette in the conical flask and titrate against KOH solution
by using Phenolphthalein as an indicator.
Endpoint – Colorless to violet.
N1V1 = N2V2
N1 = N2V2
V1
Where
N1 = Normality of KOH
V1 = Volume of KOH
N2 = Normality of Oxalic Acid
V2 = Volume of Oxalic Acid
PREPARATION OF 0.1 N OF ALCOHOLIC KOH SOLUTION
Dissolve 2.8 gms of KOH flakes (potash alkali) in 250ml of methanol in a 500ml
volumetric flask. After complete dissolution makeup up to the mark with
methanol.
STANDARDIZATION OF KOH SOLUTION:
Make a standard 0.1 N Oxalic Acid solution and take 25ml of this solution with
the help of the pipette in the conical flask and titrate against KOH solution
by using Phenolphthalein as an indicator.
Endpoint – Colorless to violet.
N1V1 = N2V2
N1 = N2V2
V1
Where
N1 = Normality of KOH
V1 = Volume of KOH
N2 = Normality of Oxalic Acid
V2 = Volume of Oxalic Acid
PREPARATION OF STANDARD 0.1 N DIBUTYL-AMINE SOLUTION.
Weigh accurately 12.925gm.of Dibutyl amine (LR) in a 1000ml volumetric flask.
Make up the volume up to the mark by shaking with Toluene (LR).
Keep it in the volumetric flask under stoppered conditions.
This is the standard 0.1N Dibutylamine solution.
PREPARATION OF STANDARD 0.1 N SODIUM THIOSULPHATE
Weigh accurately 25gm.of Sodium Thiosulphate in a 1000ml volumetric flask.
Make up the volume up to the mark by shaking it with hot distilled water.
Keep it in the volumetric flask in a cool & dirt place under stopper conditions.
This is the standard 0.1N Sod. Thiosulphate solution.
To improve the life of 0.1N Sod. In thiosulphate solution add 0.1gm of Na2CO3.
PREPARATION OF 0.5 N OF AQ.KOH SOLUTION
Dissolve 14 gm of KOH Flasks (Potash Alkali) in 200 ml of distilled water in a 500 ml volumetric flask. After complete dissolution make up to mark with distilled water.
STANDARDIZATION OF KOH SOLUTION
Transfer 10 ml KOH solution by a pipette to a 100 ml volumetric flask and make up
the volume up to the mark with distilled water. Take this solution in a
burette.
Pipette out 25ml of standard 0.1N oxalic acid solution and transfer into a
100ml conical flask. Titrate with the KOH solution using Phenolphthalein
as an indicator.
End
Point - Colourless
to Voilet
Normality of original in KOH
solution = 10x25x0.1= 25
Vb
Vb = Volume
of KOH Solution
PREPARATION OF 0.5 N OF ALCOHOLIC KOH SOLUTION
Dissolve 14 gm of KOH Flasks (Potash Alkali) in 200 ml of distilled water in a 500 ml volumetric flask. After complete dissolution make up to mark with
distilled water.
STANDARDIZATION OF KOH SOLUTION
Transfer 10 ml KOH solution by a pipette to a 100 ml volumetric flask and make up the volume up to the mark with distilled water. Take this solution in a burette.
Pipette out 25 ml of standard 0.1N oxalic acid solution and transfer it into a 100 ml conical flask. Titrate with the KOH solution using Phenolphthalein as an indicator.
End Point - Colorless to Violet
Normality of original in KOH solution = 10x25x0.1= 25
Vb
Vb = Volume of KOH Solution