I just got some 99.6% pure oxalic acid dihydrate to use for KMnO titration, to standardize the KMnO for further iron content titrations.
In all write-ups I see anhydrous oxalic acid being used for KMnO titration. Theoretically I could either bake my acid and get anhydrous form or use as is and just measure it out using 126.065 g/mol weight instead of 90.03g/mol.
My burrette is a 50ml with 0.1ml divisions, so really a 1% accuracy is all I can reasonably hope for.
My question is this: Do i need to dehydrate the oxalic acid and use the 90.03g/mol weight or can i trust that most of it is in dihydrate form and I can just use the 126.065 g/mol?
Sold by Florida Laboratories, advertised as 99.6% pure oxalic. But it was a 5lb bag for $15, so hopefully its that pure...? Definitely not sure about the likely fractions of mono-hydrate and dihydrate and anhydrous...
What do you all think?
Trying to standardize KMnO for iron content determination. And really, that iron content determination only needs to be a ball-park figure, say within 5% to 10% of the reading.