Question

What is the buffer-component concentration ratio, [NO2- ]/[HNO2], of a buffer that has a pH of 2.96) Ka of HNO2 = 7.1 x 10-4.

Answer 1

Since this is a buffer solution we will use the famous Henderson-Hasselbalch equation,

It is given by,

Now pH = 2.96

Ka = 7.1*10^-4

Now we will first convert Ka to pKa,

pKa= - log([Ka]) = - log(7.1*10^-4 ) = 3.1487

Substituting the values of pH and pKa in the handerson equation