Dissolve 7.612 g in sufficient water to produce 1000 ml
To 20 ml of 0.1M silver nitrate VS add 25 ml of water, 2 ml of 2M nitric acid and 2 ml of ammonium iron(III) sulphate solution R2 and titrate with the ammonium thiocyanate solution until a reddish yellow colour is obtained.
Each ml of 0.1M silver nitrate VS is equivalent to 7.612 mg of NH4SCN.
Perform a duplicate and calculate the molarity factor (MF)
Note down the average value
1) Restandardise before use
2) Discard the solution after 30 days.
3) For storage and labeling follow the general procedure.