What is the (H3O+) and
the ph of a buffer that consists of 0.25M HNO2 and 0.69M KNO2?
(Ka of HNO2 = 7.1 x 10^-4)
is this right?
pH of acidic buffer
pH = pka + log(salt/acid)
pka = -log ka = -log(7.1*10^(-4)) = 3.15
= 3.15+log(0.25/0.69)
pH = 2.71
[H3O+] = 10^-pH = 10^(-2.71) = 0.001945 M
Thank you.
2 answers
In the HH equation didn't you say it was salt/acid. KNO2 is the salt; HNO2 is the acid.
[base] > [acid] so your pH should be larger than pka. check DrBob's answer :)