pH and pOH


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kanikubari
Posts: 30
Joined: Fri Dec 07, 2018 12:18 am

pH and pOH

Postby kanikubari » Sun Jan 20, 2019 8:44 pm

How do you know which one to solve for? For instance on 6B.5.

annabel 2A
Posts: 67
Joined: Fri Sep 28, 2018 12:18 am

Re: pH and pOH

Postby annabel 2A » Sun Jan 20, 2019 9:03 pm

What does the problem say? I think generally it tells you which to solve for.

Esther Lee 4H
Posts: 67
Joined: Fri Sep 28, 2018 12:29 am

Re: pH and pOH

Postby Esther Lee 4H » Sun Jan 20, 2019 9:06 pm

dont know what the question says but I think for most questions it specifies to solve for either one or the other or both

Kavvya Gupta 1H
Posts: 35
Joined: Fri Sep 28, 2018 12:21 am

Re: pH and pOH

Postby Kavvya Gupta 1H » Sun Jan 20, 2019 9:25 pm

I don't know what the problem says but usually, it will tell you what to solve for in the problem. Given the reaction, you will know what you have to solve for. For instance if it NH3 + H20 -> NH4+ + OH- you would solve for Kb and pOH and if it was HCl + H20 -> Cl- + H30+.

Tessa Lawler 1A
Posts: 57
Joined: Fri Sep 28, 2018 12:18 am

Re: pH and pOH

Postby Tessa Lawler 1A » Sun Jan 27, 2019 10:03 pm

If it doesn't tell you explicitly, just go off of what's present in the equation. Which do you end up with in the products - H3O+ or OH-? If it's OH-, then pOH. If it's H3O+, then pH. And of course you can always calculate one once you have the other using the equation pH + pOH = 14.

Luis_Yepez_1F
Posts: 50
Joined: Fri Sep 28, 2018 12:18 am

Re: pH and pOH

Postby Luis_Yepez_1F » Sun Jan 27, 2019 10:11 pm

Usually the question will ask you to solve for one or the other.

505211599
Posts: 60
Joined: Fri Sep 28, 2018 12:28 am

Re: pH and pOH

Postby 505211599 » Mon Jan 28, 2019 12:54 am

The question will tell whether to solve for ph or pOH.

Casandra
Posts: 65
Joined: Fri Sep 28, 2018 12:17 am

Re: pH and pOH

Postby Casandra » Mon Jan 28, 2019 1:04 am

The question will ask you to solve for pH or pOH, and the problem will also give you sufficient information to be able to solve for this.

Kaylee Kang 1G
Posts: 65
Joined: Fri Sep 28, 2018 12:24 am

Re: pH and pOH

Postby Kaylee Kang 1G » Mon Jan 28, 2019 10:12 am

The probable will typically tell you whether to solve for pH or pOH.

Lauren Huang 1H
Posts: 60
Joined: Fri Sep 28, 2018 12:16 am

Re: pH and pOH

Postby Lauren Huang 1H » Mon Jan 28, 2019 8:50 pm

Also, when your chemical reaction includes H30+, you are finding the pH, and when it includes OH-, you are finding the pOH. Make sure to use the equation pH+pOH=14 if you are trying to convert between the two.

Mona El Masri 1F
Posts: 34
Joined: Fri Sep 28, 2018 12:20 am

Re: pH and pOH

Postby Mona El Masri 1F » Mon Jan 28, 2019 9:07 pm

pOH- base
pH-acid

then you can use the pOH+pH=14 to solve for the other one

Krista Mercado 1B
Posts: 60
Joined: Fri Sep 28, 2018 12:26 am

Re: pH and pOH

Postby Krista Mercado 1B » Wed Jan 30, 2019 10:36 pm

The question will tell you which to solve for.

905084274
Posts: 42
Joined: Fri Sep 28, 2018 12:22 am

Re: pH and pOH

Postby 905084274 » Wed Jan 30, 2019 10:40 pm

Typically if you are given a base, you solve for pOH, but if you are asked to find the pH, then you must convert from pOH to pH by using this formula: -14.00 = pOH + pH. Or 14.00 - pOH = pH

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

Re: pH and pOH

Postby MichelleRamirez_2F » Sun Feb 10, 2019 3:38 pm

Usually the problem you are solving will tell you which one to solve for. In some occasions you may have to solve for both for the same problem.

Anna O 2C
Posts: 98
Joined: Fri Sep 28, 2018 12:19 am

Re: pH and pOH

Postby Anna O 2C » Sun Feb 10, 2019 10:30 pm

Often times if they don't say it outright, you can infer through whether they are referring to the concentrations of acids or bases in a solution.

Nicolle Fernandez 1E
Posts: 56
Joined: Fri Sep 28, 2018 12:25 am
Been upvoted: 1 time

Re: pH and pOH

Postby Nicolle Fernandez 1E » Mon Feb 11, 2019 11:11 am

If it doesn’t say specifically look at the products as OH would be pOh and H3O would be pH, sometimes it will tell you specifically

madisondesilva1c
Posts: 91
Joined: Fri Sep 28, 2018 12:16 am

Re: pH and pOH

Postby madisondesilva1c » Tue Feb 12, 2019 1:08 pm

It is always best to go with what is given, if OH is formed, then solve for pOH and then 14-pOH to find pH. If H+ is a product of the disassociation, then solve for pH and then use 14-pH if they are asking for pOH?

Ashe Chen 2C
Posts: 31
Joined: Mon Jan 07, 2019 8:23 am

Re: pH and pOH

Postby Ashe Chen 2C » Sat Feb 16, 2019 9:45 pm

The problem should specify, but if not it is usually safe to assume you should calculate for what is given, ie if the reaction forms H+ ions you should solve for pH and if OH- ions are formed solve for pOH.

jocelyntzeng
Posts: 59
Joined: Fri Sep 28, 2018 12:18 am

Re: pH and pOH

Postby jocelyntzeng » Sat Mar 16, 2019 12:56 pm

it will ask you specifically but usually it is pH


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