In: Chemistry
a) What happens when you add acid to a solution of 0.1 M HNO2 and 0.1 M KNO2? Write a chemical equation if relevant.
b) Why doesnt the same kind of reaction occur when you add acid to a solution of 0.1 M HNO3 and 0.1 M KNO3?
pKa of HNO2 = 3.15, pKa of HNO3 = -1.3,
pKa of acid determines its acidic nature, where,
pKa is inversely proportional to acidic nature
Hence, H+ will be donated by an acid having low pKa
HA + 2HNO2 ----> A- + NO+ + H2O
HA + KNO2 ------> KA + HNO2
Here HNO3 is more stronger acid because of its low pKa value than HNO2, Hence the reactions values differ.
HA + HNO3 -----> NO3- + H2A+
HA + KNO3 ----> HNO3 + KA
Hence the reaction of acids will be different with HCl and HA.