The question is "Calculate [HY3-
] in a solution prepared by mixing 10.0 mL of 0.01 M VOSO4
, 9.90 mL of 0.01 EDTA, and 10.0 mL of buffer with a pH of 4.00".
The answer is to first find [VO2+
], and then [Y4-
] (= [VOY2-
] x K6
)) and use that to find [HY3-
] which is through the equation ([H+
I just don't understand why we are using K6
(derived from pK6
) and using that equation to find HY3-
. Is this what we do if we want to find any of the fractional compositions of EDTA or just for HY3-
? What made us use Y4-
instead of anything else?
P.S.: I posted this question yesterday but I did not format the post properly. I reposted it here now with proper formatting