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Chemistry - Edexcel Question - A2

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Assi1993:
hello all! =)
can some1 define Ka, pKa and pH for me :S im confused!!

Deadly_king:

--- Quote from: Assi1993 on November 10, 2010, 05:17:05 pm ---hello all! =)
can some1 define Ka,pKa and pH for me :S im confused!!

--- End quote ---

Hi Assi, it has been a long time since we last heard from you. ;)

pH
pH is a measure of the concentration of H+ ions in aqueous solutions. It is calculated as shown :
pH = - log [H+]
Acid dissociation constant Ka
The acid dissociation constant Ka is applicable to weak acids only.

It is a measure of the strength of an acid. The bigger the value of Ka, the stronger is the acid. It is calculated as shown :

Example : CH3CO2H <=> CH3CO2- + H+

Hence Ka of ethanoic acid is => Ka = [CH3CO2-][H+] / [CH3CO2H]

pKa

pKa is a measure of the strength of an acid. The smaller the value of pKa, the stronger the acid. It is calculated as shown :
pKa = - log Ka
Now, there is also Kb which is the base dissociation constant. It's similar to Ka except that it's for bases. ;)

Hope it helps :)

Assi1993:
thnxx alot DK :D
yeah!..
hw did ur exams go?

Deadly_king:

--- Quote from: Assi1993 on November 11, 2010, 11:17:16 am ---thnxx alot DK :D
yeah!..
hw did ur exams go?

--- End quote ---

Hehe................anytime :)

Hmm..............there have good and bad. Can't say for sure :(

But I did my best ;)

How about you? How have you been doing?

Assi1993:
im doin fine :)
and i didnt give any exam lately..but yeah trying to study :p
happy eid in advance :) what r ur eid plans insha-Allah :D

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