if the volumes of the weak acid and its conjugate base are equal than the pH=pka of the solution. You know this by looking at the Henderson–Hasselbalch equation.
pH=pka+log[A^-]/[HA]
Where
A^-=NaNO2
and
HA= HNO2
Since the concentrations are equal, the above equation becomes the following:
pH=pka+log[1]
The log of 1 is 0, so the equation becomes
pH=pka
Where
pka=-log[Ka]
You can do the rest.
Suppose you are assigned to prepare a buffer of 0.10M HNO2 (Ka=1.7 x 10^-4) and 0.10M NaNO2 by mixing equal volumes of both solutions. What is the pH of the resultant solution?
How would I first start this question? I have no clue what the steps are to be frank.
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