Answer :
(A) The number of moles of
ions per liter is, 0.1 moles/L
(B) The number of molecules of
ion is, 
(C) The pH of the solution will be, 4
<u>Solution for part A :</u>
First we have to calculate the pOH of the solution.
As we know that,

Now we have to calculate the moles of
ion per liter.
![pOH=-\log [OH^-]\\\\1=-\log [OH^-]](https://tex.z-dn.net/?f=pOH%3D-%5Clog%20%5BOH%5E-%5D%5C%5C%5C%5C1%3D-%5Clog%20%5BOH%5E-%5D)
![[OH^-]=0.1moles/L](https://tex.z-dn.net/?f=%5BOH%5E-%5D%3D0.1moles%2FL)
<u>Solution for part B :</u>
First we have to calculate the
ion concentration.
![pH=-\log [H^+]\\\\13=-\log [H^+]](https://tex.z-dn.net/?f=pH%3D-%5Clog%20%5BH%5E%2B%5D%5C%5C%5C%5C13%3D-%5Clog%20%5BH%5E%2B%5D)
![[H^+]=10^{-13}moles/L](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3D10%5E%7B-13%7Dmoles%2FL)
Now we have to calculate the number of molecules of
ion
As, 1 mole contains
number of molecules of
ion
So,
moles contains
number of molecules of
ion
<u>Solution for part C :</u>
![pH=-\log [H^+]\\\\pH=-\log (1\times 10^{-4})](https://tex.z-dn.net/?f=pH%3D-%5Clog%20%5BH%5E%2B%5D%5C%5C%5C%5CpH%3D-%5Clog%20%281%5Ctimes%2010%5E%7B-4%7D%29)
