0.1 M Preparation & standardization of ceric ammonium sulphate

1.0 OBJECTIVE:

Preparation & standardization of 0.1 M ceric ammonium sulphate 

2.0 SCOPE:

The Procedure is applicable Preparation & standardization of ceric ammonium sulphate  in company Name.

3.0 RESPONSIBILITY

3.1 QC-Chemist

4.0 ACCOUNTABILITY

4.1 Head – Quality control

4.2 Head – Quality Assurance  

5.0  PROCEDURE: 

5.1 PREPARATION

5.1.1 Dissolve 65 g of ferric  ammonium sulphate, with the aid of gentle heat, in a mixture of 30ml of sulphuric acid and 500ml of water. Cool, filter the solution, if turbid, and dilute to 1000 ml with water. 

5.2 PRINCIPLE

Ceric ammonium sulphate is titrated with Arsenic trioxide solution (Primary standard) in presence of sodium hydroxide, and osmic acid solution.

As2 O3+ 2NaOH → 2NaAsO2+ H2O

NaAsO2+ 2H 2O→ NaH2AsO4+ 2H+ + 4e

Ce4+ + e- → Ce3+

5.3 STANDARDIZATION

5.31 Standardise the solution in the following manner. Weigh accurately about 0.2 g of arsenic trioxide, previously dried at 105°for 1hour, and transferred to a 500ml conical flask. 

5.3.2 Wash down the inner walls of the flask with 25 m1 of a 8.0 per cent w/v solution of sodium hydroxide, swirl to dissolve, add 100 ml of water and mix. 

5.3.3 Add 30 ml of dilute sulphuric acid, 0.15 ml of osmic acid solution, 0.1 ml of ferrroin sulphate solution and slowly titrate with the ceric ammonium sulphate solution until the pink colour is changed to a very pale blue, adding the titrant slowly towards the end-point.

5.4 Calculation:

M = W x RM / V x E

W= Weight of arsenic trioxide

RM=Required molarity

E=Equivalent weight factor 

V=Volume of Cerric ammonium sulphate

W=0.2gm

RM=0.1M

V=40ml

E=0.004946

M= 0.2x0.1/40 x 0.004946 = 0.1010 M

6.0 ANNEXURES

Nil