Answer to Question #64312 in Chemistry for Sanjukta Ghosh

Question

How do I calculate Equ wt of O2?
We needed to calculate the conc.of O2 present in water sample by Winkler's method.
Link to the procedure and reactions: http://dropcanvas.com/6su7m
We had to use this formula: c(O2) (mg/L)=(V1×N×E×1000)/V4
where
V1= Vol of titrant Na2S2O3
V4=Vol of analyte
E=Equ wgt of O2
N=Normality of Na2S2O3 sol
The process and reactn involved are here: