## pH calculation

MichelleRamirez_2F
Posts: 63
Joined: Fri Sep 28, 2018 12:28 am

### pH calculation

When we are loking for pH why is pH= log10[H30]? How do we know what the value of [H3O] is?

Tiffany_Cacy_3D
Posts: 70
Joined: Fri Sep 28, 2018 12:24 am

### Re: pH calculation

Usually this value is given to you as the molarity of the solution or you are given moles and volume of a certain solution and you have to find the molarity by dividing moles of solute by liters of solution to find the molarity to in turn plug into the pH equation.

Tony Chung 2I
Posts: 60
Joined: Fri Sep 28, 2018 12:19 am

### Re: pH calculation

This is normally given to you in the problem as a molarity

Lydia Luong 4L
Posts: 59
Joined: Fri Sep 28, 2018 12:24 am

### Re: pH calculation

The molarity is usually given to you!

Michael_Navarro_1H
Posts: 29
Joined: Fri Sep 28, 2018 12:17 am

### Re: pH calculation

To clarify, if you are dealing with a strong acid, the molarity of the acid will equal the molarity of the H3O+ in solution. So for example, if you were given a solution of HCl with molarity 0.20 M and were asked to calculate the pH of the solution, the molarity of the H3O+ ions in solution would also be 0.20 M and the pH would be determined using -log[0.20].

Return to “Calculating pH or pOH for Strong & Weak Acids & Bases”

### Who is online

Users browsing this forum: No registered users and 1 guest