Answer:
The ratio (NO2-)/(HNO2) is 2.094
Explanation:
Using H-H equation for nitrite-nitrous acid buffer:
pH = pKa + log [NO2-] / [HNO2]
Where pH is 3.47
pKa is -log Ka = 3.149
3.47 = 3.149 + log [NO2-] / [HNO2]
0.321 = log [NO2-] / [HNO2]
10^0.321 = [NO2-] / [HNO2]
2.094 = [NO2-] / [HNO2]
The ratio (NO2-)/(HNO2) is 2.094
