pH of 0.1M solution of NaA (sodium salt of weak acid HA) is 8.92.Calculate pK_(a) of HA.If a drop HPh(pK_("in")=9.52) be added to the above solution.predict whether the pink colour will visible or not the under the medical fact that our eyes can see the pink colour if the mole % of ionised form of indicated is 25% or more.

pH of 0.1M solution of NaA (sodium salt of weak acid HA) is 8.92.Calcu

1.	pH of 0.1M solution of NaA (sodium salt of weak acid HA) is 8.92.Calculate pK_(a) of HA.If a drop HPh(pK_("in")=9.52) be added to the above solution.predict whether the pink colour will visible or not the under the medical fact that our eyes can see the pink colour if the mole % of ionised form of indicated is 25% or more.
Answer» Solution :`pH=(1)/(2)(pK_(a)+pK_(w)+logc)` `8.92=7+(1)/(2)pK_(a)+(1)/(2)(-1)` `(1)/(2)pK_(a)=8.92-6.5=2.42` `pK_(a)` of `HA=4.84` `:.pK_(a)=pK_("in")+LOG""([LN^(-)])/([HLN])` `=8.92=9.52+log""([ln^(-)])/([Hln])` `=8.92=9.52+log"([ln^(-)])/([Hln])` `([ln^(-)])/([Hln])=(ionised)/(unionised)=(1)/(4)` Since ionised from `%=(1)/(1+4)xx100=20%` PINK colour will not be visible.