Answer
pH of buffer = 3.63
Work Step by Step
1
(A) Given :
1. pH of the buffer = 5.44
2. Ka of Acid (HPr) = 1.3 x 10^-5
2
(B) Formulae :
1. Henderson - Hasselbalch equation of a buffer : pH = pKa + log [base] / [acid]
2. pKa = -log(Ka)
3
(C) Solution :
1. pKa = -log (Ka)
= -log (1.3 x 10^-5)
= 4.88 .... (1)
2. pH = pKa + log [base] / [acid]
5.44 = 4.88 + log ([Pr-] / [HPr])
0.56 = log ([Pr-] / [HPr])
[Pr-] / [HPr] = 10^(0.56) = 3.63
Hence, the component concentration ratio [Pr-] / [HPr] is equl to 3.63
4
(D) Answer :
pH of buffer = 3.63
