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

explanation:

metals have excess of electrons whereas non-metals have deficiency of electrons. thus, in order to gain stability metals easily donate their electrons to the non-metals.

for example, electronic configuration of sodium is and electronic configuration of phosphorous is .

when a phosphorous atom and sodium atom combine together then sodium will donate is extra one electron to the phosphorous atom. as a result there will be formation of ionic bond between sodium and phosphorous.

the reaction will be as follows.

there, are three sodium sodium atoms and each of them will donate its one extra electron to phosphorous atom. thus, the sub-shell of phosphorous gets completely filled.  

thus, we can conclude that electrons are transferred from atoms of sodium to atoms of phosphorous. this transfer makes the sodium atoms donate one electron and the phosphorous atoms to gain one electron. as a result, the sodium and phosphorus atoms strongly attract each other.