I need to find the pKa and Ka value of CH3COOH for my Acid-Base titration experi
ID: 552283 • Letter: I
Question
I need to find the pKa and Ka value of CH3COOH for my Acid-Base titration experiment. It’s pH before titration is 2.37 pH at equivalence point is 9.17 [H3O+] before titration is .00427 [H3O+] at equivalence point is 0.99 (Don’t know if it’s needed but the midpoint on the titration curve is (5.5ml, 7.49ph) . . Step by step explanation would be helpful!I need to find the pKa and Ka value of CH3COOH for my Acid-Base titration experiment. It’s pH before titration is 2.37 pH at equivalence point is 9.17 [H3O+] before titration is .00427 [H3O+] at equivalence point is 0.99 (Don’t know if it’s needed but the midpoint on the titration curve is (5.5ml, 7.49ph) . . Step by step explanation would be helpful!
I need to find the pKa and Ka value of CH3COOH for my Acid-Base titration experiment. It’s pH before titration is 2.37 pH at equivalence point is 9.17 [H3O+] before titration is .00427 [H3O+] at equivalence point is 0.99 (Don’t know if it’s needed but the midpoint on the titration curve is (5.5ml, 7.49ph) . . Step by step explanation would be helpful!
Explanation / Answer
If your aim is to determine pKa and Ka , it is easy to determine
You know of equivalence point from graph
Half equivalence point = equivalence point/2
at half equivalence point
pH = pKa
reason for this is from Henderson - Hasselbalch equation
pH = pka + log([A-]/[HA])
[A-] =[ CH3COO- ]
[HA] =[ CH3COOH]
at half equivalence point
[CH3COO- ] = [ CH3COOH ]
so,
pH = pKa + log(1)
pH = pKa
So, you note down the pH corresponding to half equivalence point and that pH is the pKa value
pKa = - logKa
From this relation you can find out Ka value
Accepted value of pKa and Ka value of CH3COOH are
pKa = 4.75
Ka = 1.8×10^-5