A sample of pure water at 303 K is found to have a pH of 691

A sample of pure water at 303 K is found to have a pH of 6.916. To that sample concentrated HCI was added until the pH of the solution (at 303 K) is 4.493. What is the value for poH at the same temperature?

Solution

pOH = 2*6.916 - 4.493 (since the mid point or neutral pH value is 6.916, the extreme value is 2*6.916)

= 9.339

Therefore pOH at the same temperature is 9.339