Winkler method for dissolved oxygen

[fibreweb]

I have been asked to make up a sodium iodate solution for senior chemistry to measure the dissolved oxygen in water.

The recipe calls for 50 gm of NaOH and 15 gms sodium Iodate in 100 mls water which I figured was 12M solution of NaOH.

This sounds REALLY strong and I was wondering if anyone could tell me if the procedure was still able to be done with a somewhat weaker solution as 11-12 arn't allowed that strong. 12 M is teacher only.

Wendy

[lada]

Yes my method says the same. 50-60%NaOH and 135g Sodium Iodide (NaI)in 1L.
Do not use iodate.
The teacher must determine if he still wants to use it and must do a RA for this.
Lada

[jat]

We have done this prac for years with no trouble- the teacher or myself just add it for the students- you are only using 2mls at a time and with the appropriate PPE ie safety glasses we have not had a problem. If you do not have Sodium Iodide(13.5g) you can use Potasium Iodide (15g)

John