Re: Making Ferric Oxalate

Keith Dowsett (kdowsett@rpms.ac.uk)
Mon, 21 Oct 1996 09:46:29 -0100

>Chemical Old Timers
>
>I know that I am benighted but I still use ferric oxalate although aware of
>the alternatives.
>
>I have made up a number of batches using the peroxide method in Dick Stevens'
>book. Now I no longer seem to be able to get 30 % ( is that 30 vol ? )
peroxide
>and adding 28.5 or 20 to the ferrous oxalate plus oxalic acid mixture produces
>lots of heat and gas and bubbles ( bit of deja vu there) it produces no ferric
>oxalate solution. The only other difference in method was to use an 'inert'
>plastic stirrer rather than a glass rod. Is it the rod or the peroxide causing
>the problem ?
>
>Terry King

Hi,

A back of the envelope calculation reveals that 30 vol. hydrogen peroxide
contains 45.5 grams of peroxide per liter, while 28% contains 280 grams per
liter. You can measure the peroxide content by decomposing it and measuring
the volume of gas produced. Just remember that it generates a whole lot of
heat too.