Answer:-
A) 3.745
B) 2 x 10^-13 M [H+]
pOH = 1.3
Explanation:-
A) From the question we see
The strength of HCl solution = 1.8 x 10^-4 M.
The M stands for molarity which is moles / Litre.
HCl is a monobasic acid. So the number of moles of Hydrogen ion H+ HCl can give is the same as the value of it’s strength in moles per litre.
The hydrogen ion concentration [H+] is therefore 1.8 x 10^-4.
The formula for pH is
pH = - log [ H+ ]
= - log [1.8 x 10^-4]
= 3.745
B) From the question we see
The strength of KOH = 0.05 M
The M stands for molarity which is moles / Litre.
KOH is a monoacidic base. So the number of moles of Hydroxyl ion OH- KOH can give is the same as the value of it’s strength in moles per litre.
The Hydroxyl ion concentration [OH-] is therefore 0.05
The relation between [OH-] and [H+] is
[H+] x [ OH-] = 10^-14
[H+] = 10^-14 / [OH-]
= 10^-14/ 0.05
= 2 x 10^-13 M
Using the relation between pH and [OH-]
pOH = - log [OH-]
= -log [0.05]
= 1.3