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Chemistry Forums for Students => Analytical Chemistry Forum => Topic started by: LeeH on December 06, 2005, 07:31:04 PM

Title: Conditional Formation Constant, EDTA
Post by: LeeH on December 06, 2005, 07:31:04 PM

I know how to calculate this question with Kf value that I have but i cant seem to find the aY4- value. I have a list of the values for pH of 0,1,2,3,4 but not for a number iwth a decimal. I could really use some help.
thanks
heres the question

Calculate the conditional formation constant for the formation of the EDTA complex of Ca2+ at a pH of 8.6

Title: Re:Conditional Formation Constant, EDTA
Post by: Borek on December 06, 2005, 07:35:52 PM

Not sure what you are talking about - do you need Ka1, Ka2, Ka3 and Ka4? If so, download my BATE, demo version database contains all EDTA dissociation constants.

Title: Re:Conditional Formation Constant, EDTA
Post by: LeeH on December 06, 2005, 07:46:10 PM

The conditional formation constant is k' = (alphaY4-)(Kf)
I know the Kf value which is 4.9E10.
I know the K1, k2, k3, k4, k5 k6 values i just cant seem to get a right answer from the equation used to find the alphaY4- value

Title: Re:Conditional Formation Constant, EDTA
Post by: LeeH on December 06, 2005, 09:47:54 PM

I figured it out.
thanks anyways