EDTA solution becomes slurry

EDTA will not dissolve until pH 8 is reached, hence the "white slurry". Simply
keep adding NaOH while measuring pH (I suggest using a pH paper, not an
electrode). When you get near pH=8 you will see sudden clearance of the
solution. You can definitely start with NaOH pellet (add a little and let it
dissolve completely before adding more) and use NaOH solution only for final
adjustment. Preparing EDTA solution is a slow process...
Yoram





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Yoram Gerchman <[Only registered users see links. ].il> writes:

To save some time and frustration, you need about equimolar amounts of
NaOH and EDTA to dissolve the EDTA. Effectively, you are making
trisodium EDTA from disodium EDTA. You can add almost enough pelleted
NaOH to reach this point, then titrate with pH paper and 5M NaOH
solution to reach pH 8.0. Just a reminder, you cannot make a 1 M
solution -- the stock solution is 500 mM.

On May 31, 5:41*pm, Tom Knight <[Only registered users see links. ].edu> wrote:

Tom, is there a reference for this? A colleague is attempting to make
1M EDTA, with great difficulty.
I guess I will search for solubility info.

Thanks in advance,

Brian Cady