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pKa vs. pH

Posted: Thu Jan 24, 2019 11:17 am
by Lumbini Chandrasekera 1B
Why isn't pKa the same as pH?

Re: pKa vs. pH

Posted: Thu Jan 24, 2019 11:21 am
by katherinemurk 2B
pKa is a the -log of the acid dissociation constant, it is a measure of acid strength. pH is a measure of the concentration of H+ ions.

Re: pKa vs. pH

Posted: Thu Jan 24, 2019 1:36 pm
by Karan Thaker 2L
They're both logarithmic expression of completely different things. pKa is a logarithmic expression of Ka values while pH is a logarithmic expression of hydrogen ion concentration.

Re: pKa vs. pH

Posted: Thu Jan 24, 2019 5:52 pm
by Kyither Min 2K
pKa stands for -log of Ka and pH stands for -log of Hydronium ions. Consider the p as a function rather than a symbol. All the p does is mathematically change the value, similar to a negative sign or derivative. Ka is the dissociation of an acid or the equilibrium constant for the acid whereas H is just the concentration of H3O+. The two measure different things.

Re: pKa vs. pH

Posted: Sun Jan 27, 2019 10:44 pm
by Anand Narayan 1G
This is because pKa is a the -log of Ka, the acid dissociation constant, it is a measure of acid strength. pH, on the other hand is a measure of the concentration of H+ ions.

Re: pKa vs. pH

Posted: Sun Jan 27, 2019 11:14 pm
by 405021651
The pKa is the -log(Ka)

Re: pKa vs. pH

Posted: Mon Jan 28, 2019 12:39 am
by 505211599
The pKa is the -log(Ka) and pH is -log(H+)

Re: pKa vs. pH

Posted: Wed Jan 30, 2019 4:21 pm
by abbydouglas1K
pKa and pH measure different quantities. pKa measurers acid strength and pH measures H+ concentration, which are similar but Ka is used to find pKa as opposed to a molar cpncenztrartion of H+ ions in a solution.

Re: pKa vs. pH

Posted: Wed Jan 30, 2019 6:34 pm
by JacobHershenhouse3G
Don't let yourself be confused by similar notation because they mean dramatically different things. p just means -log, so in this case you are taking the negative log of a constant and of a concentration, therefore it is evident that the interpretation of these numbers mean different things. Both values gives you insight on how strong or weak an acid or base. Yet, taking the pka of an acid base reaction gives you perspective in relation to pKw=1e-14 and pH does so on a scale of 0 to 14.

Re: pKa vs. pH

Posted: Wed Jan 30, 2019 6:53 pm
by Zubair Ahmed 1L
The pKa and the pH represent two different things. The pKa is the -log(Ka) and can be used to determine the strength of an acid. On the other hand, the pH is the -log(H+) concentration.

Re: pKa vs. pH

Posted: Wed Jan 30, 2019 7:42 pm
by Nina Do 4L
pKa is the -log of the Ka value and Ka*kB=1x10^-4 so you can find out the value of Ka/pka if you're given the value of Kb.

pH is the -log of H+ or H3O+.

The 'p' is -log-ing different values, therefore they are different. Hope this helps.

Re: pKa vs. pH

Posted: Wed Feb 06, 2019 9:28 am
by Ricardo Martin 1J
pH is the concentration f hydrogen ions in the solution.

Re: pKa vs. pH

Posted: Fri Mar 15, 2019 9:49 am
by Ashley P 4I
pKa= -log of Ka
pH stand= -log of Hydronium ions.

Re: pKa vs. pH

Posted: Fri Mar 15, 2019 9:38 pm
by Nghi Nguyen 2L
pKa = -log(Ka)
pH = -log(H+)

Re: pKa vs. pH

Posted: Sun Mar 17, 2019 4:52 pm
by Roberto Gonzalez 1L
pH can be solved for by taking the -log of the concentration of hydronium ions, and therefore quantitatively describes the acidity or basicity of a solution. pKa is found taking the -log of the ionization constant of an acid, and can therefore be used to understand the strength of an acid.

Re: pKa vs. pH

Posted: Sun Mar 17, 2019 5:30 pm
by Anita Wong 1H
pka is in reference to ka whereas ph is in reference to H+