Write the acid-dissociation reaction of nitrous acid (HNO2) and its acidity constant expression.
HNO2 + H2O ==> H3O^+ + NO2^-
Ka = (H3O^+)(NO2^-)/(HNO2)
H2+ 2NO-
8 = = = D
The acid-dissociation reaction of nitrous acid (HNO2) can be represented as follows:
HNO2 (aq) ⇌ H+ (aq) + NO2- (aq)
In this reaction, nitrous acid (HNO2) dissociates to form a hydrogen ion (H+) and a nitrite ion (NO2-).
The acidity constant expression, also known as the acid dissociation constant or Ka, represents the equilibrium constant for the dissociation reaction and is written as follows:
Ka = [H+][NO2-] / [HNO2]
In this expression, [H+] represents the concentration of hydrogen ions, [NO2-] represents the concentration of nitrite ions, and [HNO2] represents the concentration of nitrous acid. The square brackets indicate the concentration of each species, which is typically expressed in molarity (M).
The value of the acidity constant determines the strength of the acid. A higher Ka value indicates a stronger acid, while a lower Ka value indicates a weaker acid.