A110.0 ml sample of 0.040 m ca2+ is titrated with 0.040 m edta at ph 9.00. the value of logkf for the ca2+−edta complex is 10.65 and the fraction of free edta in the y4− form, − , is 0.041 at ph 9.00. what is k′f , the conditional formation constant, for ca2+ at ph 9.00?

Answer : The conditional formation constant is

Explanation :

First we have to calculate the formation constant.

As we are given that:

Thus, the formation constant is

Now we have to calculate the conditional formation constant.

The expression used as:

where,

= conditional formation constant = ?

= activity coefficient at pH 9.00 = 0.041

= formation constant =

Now put all the given values in the above expression, we get:

Therefore, the conditional formation constant is