Solution :
The relationship between pH and is pH =
The concentration of is given as
pH =
Therefore, the concentration of is
The relationship between pH and is pH =
The concentration of is given as
pH =
= 0.82
Therefore, the pH of the solution is 0.82
Now updating the ICE table for 0.15 M is as follows :
0.15 0 0
-x +x +x
0.15 - x x x
∴ Acidionization constant,
We can assume that : (0.15 - x) M = 0.15 M
Therefore, from the equilibrium table,
pH =
= 2.77
Hence the pH of 0.15 M is 2.77
Stronger acid always have a lower pH value.
The value of pH for the given solution are 0.0, 7.45, 0.82 and 2.77
So the increasing order of the acidity is :
pH = 0.0 > pH = 0.82 (0.15 M HCl) > pH = 2.77 (0.15 M ) > pH =7.45