Stoichiometric coefficients for pH/pOH

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Althea Zhao 1B
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Stoichiometric coefficients for pH/pOH

Postby Althea Zhao 1B » Sun Jan 19, 2020 7:48 pm

When we calculate the pH or pOH for strong acids and bases, do we need to raise [H3O+] or [OH-] to their stoichiometric coefficients? For example, would the pOH of Ba(OH)2 be -log[OH]^2?

Christine Honda 2I
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Re: Stoichiometric coefficients for pH/pOH

Postby Christine Honda 2I » Sun Jan 19, 2020 7:50 pm

No, you do not need to raise it to the stoichiometric coefficients because when you take the pOH you are taking the -log of the concentration of OH- ions, not the ratio of them.

gconcha
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Re: Stoichiometric coefficients for pH/pOH

Postby gconcha » Sun Jan 19, 2020 7:54 pm

No, you don't need to do that because during the process of calculating [H3O+] or [OH-], you should have already taken the stoichiometric coefficients into account in your ICE chart or KA / KB calculation

Chris Charton 1B
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Re: Stoichiometric coefficients for pH/pOH

Postby Chris Charton 1B » Sun Jan 19, 2020 7:56 pm

Raising concentrations to their stoichiometric coefficient is only required for the equilibrium equations.


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