Home > Chemistry > Solutions

Are pH and pOH related to each other?

Answer 1

Jeremiah Adams

Absolutely! In water:

#pH + pOH = 14#

Water is known to go through autoprotolysis:

#2H_2O rightleftharpoons H_3O^+ + HO^-#

This is an equilibrium reaction, measured precisely over a range of temperatures. It is a fact that at #298K#,

#[H_3O^+][HO^-]# #=# #10^(-14)# (#[H_2O]# is treated as a constant!). Now this is a mathematical equation, which I can manipulate, as long as I do the same thing to both sides.

Taking #log_10# of both sides:

#log_10[H_3O^+] + log_10[HO^-] # #=# #-14#

After reorganization,

#14# #=# #-log_10[H_3O^+] - log_10[HO^-] #

But by definition, #-log_10[H_3O^+] = pH#, and # log_10[HO^-] =pOH#.

So #pH + pOH = 14#

By signing up, you agree to our Terms of Service and Privacy Policy

Answer 2

Naomi Aronson

Yes, pH and pOH are related to each other. pH is a measure of the acidity or alkalinity of a solution, while pOH is a measure of the concentration of hydroxide ions (OH-) in a solution. The relationship between pH and pOH is given by the equation: pH + pOH = 14. This means that if you know the pH of a solution, you can calculate its pOH, and vice versa.

By signing up, you agree to our Terms of Service and Privacy Policy

Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.