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### Relationship between pH, protanation and molarity

Posted: Sat Dec 09, 2017 5:17 pm
Hi

How can pH or pOH be found
given % protonation/deprotanation and molarity?

Ty!

### Re: Relationship between pH, protanation and molarity

Posted: Sat Dec 09, 2017 8:00 pm
You use the molarity of H30+ and OH- to find the pH and pOH by taking the -log of each.
-log[H30+]=pH
-log[OH-]=pOH

### Re: Relationship between pH, protanation and molarity

Posted: Sat Dec 09, 2017 8:05 pm
For an acid, when given the initial molarity and percent deprotonation, you multiply the initial molarity by the percent deprotonation (as a decimal, so over 100) to find the concentration of H3O+ ions in solution.
You then use this concentration to find pH in the normal way (pH=-log[H3O+])

For bases, you do the same thing except for OH- ions and pOH

### Re: Relationship between pH, protanation and molarity

Posted: Thu Jan 17, 2019 4:02 pm
When solving for the percent deprotonation, is it always going to be the value you got for X (from the ICE table) divided by the initial concentration given?

### Re: Relationship between pH, protanation and molarity

Posted: Thu Jan 17, 2019 4:04 pm
Can deprotonation still be found if we are given initial concentrations for both the reactants and products?

### Re: Relationship between pH, protanation and molarity

Posted: Thu Jan 17, 2019 4:15 pm
Yes! All you need to do is divide the equilibrium concentration of the conjugate acid/base by the initial concentration of the corresponding acid and base.