Preparation of 0.1M Perchloric Acid Solution
Mix 8.5 ml. of perchloric acid with 500 ml. of anhydrous glacial acetic acid and 25 ml. of acetic anhydride, cool and add anhydrous glacial acetic acid to produce 1000 ml.
Allow the prepared solution to stand for 1 day for the excess acetic anhydride to be combined and carry out the determination of water.
If the water content exceeds 0.05%, add more acetic anhydride. If the solution contains no titrable water, add sufficient water to obtain a content of water between 0.02% and 0.05%. Allow the solution to stand for one day and again titrate the water content.
The solution so obtained should contain between 0.02% and 0.05% of water. Standardize the solution in the following manner.
Standradization 0.1M Perchloric Acid Solution
Weigh accurately about 0.350 gm. of potassium hydrogen phthalate (KHP) previously dried at 120°C for 2 hours and dissolve it in 50 ml. of anhydrous glacial acetic acid add 0.1ml crystal violet solution as an indicator and titrate with the 0.1M perchloric acid solution until the violet colour changes to emerald-green. Perform a blank determination and make any necessary corrections.
Each 1ml of 0.1M perchloric acid is equivalent to 0.02042gm of C8H5KO4
Calculation
Molarity = ------------------------------------
Volume consumed (ml) x 20.42 × 100
Preparation of 0.05M Perchloric Acid Solution
Mix 4.25 ml. of perchloric acid with 500 ml. of anhydrous glacial acetic acid and 12.5 ml. of acetic anhydride, cool and add anhydrous glacial acetic acid to produce 1000 ml.
Allow the prepared solution to stand for 1 day for the excess acetic anhydride to be combined and carry out the determination of water.
If the water content exceeds 0.05 %, add more acetic anhydride. If the solution contains no titrable water, add sufficient water to obtain the content of water between 0.02% and 0.05%. Allow the solution to stand for one day and again titrate the water content.
The solution so obtained should contain between 0.02% and 0.05% water content. Standardize the solution in the following manner.
Standradizition 0.1M Perchloric Acid Solution
Weigh accurately about 0.1750 gm. of potassium hydrogen phthalate (KHP), previously powdered lightly and heated at about 120°C for 2 hours and dissolve it in 50 ml. of anhydrous glacial acetic acid. Add 0.1ml. of crystal violet solution as an indicator and titrate with 0.05M perchloric acid solution until the violet colour changes to emerald green. Perform a blank determination and make any necessary corrections.
Each 1ml of 0.05M perchloric acid is equivalent to 0.01021gm of C8H5KO4
Calculation
Molarity = ----------------------------------
Volume consumed (ml) x 10.21 × 100