Dissolved Oxygen Question Help ! (1 Viewer)

[sando]

Do not understand at all.. some help please


Q.

25 mL sample of water was titrated against a Sodium Thiosulfate solution of 0.001M.
The average volume used to reach the end point is 11.72mL..
Assess the dissolved oxygen

 

[sando]

i understand wat DO is.. i just don't understand what calculations i need to do

 

[amyj1710]

did you ever figure that out? i'm trying to figure it out now.. HELP!

 

[Undermyskin]

You just simply need to calculate the concentration of Oxygen in that sample. Convert it into ppm. Now, go and do the calculation!

 

[JSBboag]

give me the chemical equation and i will do it for you

 

[xiao1985]

4 S₂O₃ ^2- + O₂ + 4 H ⁺ ---> 2 S₄O₆ ^2- + 2 H₂O

I think.

edit: though it seems, thiosulfate is not stable in acidic solutions. If I recall correctly, you also use iodine in the titration to figure out oxygen concentration somewhere.