What is the equilibrium constant expression (K_a)for the acid dissociation of nitrous acid HNO₂? The equation of interest is HNO₂(aq)+ H₂O(l)⇌ H₃O⁺(aq)+ NO₂^-(aq). A)K_a = ([H₃O⁺][NO₂^-])/([HNO₂][H₂O]) B)K_a = ([H₃O⁺][NO₂^-])/([HNO₂]) C)K_a = ([HNO₂][H₂O])/([H₃O⁺][NO₂^-]) D)K_a = ([HNO₂])/([H₃O⁺][NO₂^-])

Question

Quizplus · Accepted Answer

The equilibrium constant expression for the acid dissociation of nitrous acid (HNO2) into hydronium ions (H3O+) and nitrite ions (NO2-) does not include water (H2O) in the expression because water is the solvent and its concentration is considered constant and thus not included in the expression. Therefore, the correct expression is the concentration of the products (H3O+ and NO2-) divided by the concentration of the reactant (HNO2), without including water.

What Is the Equilibrium Constant Expression (Ka)for the Acid Dissociation

What Is the Equilibrium Constant Expression (K_a)for the Acid Dissociation