Question

Please predict the products of the following acid-base reaction, and predict whether the equilibrium lies to the left or to the right of the equation:

NO2-(aq) + H2O(l)

Answer 1

First, let us define Bronsted Lowry acid/base:

Bronsted Lowry acid: any species that will donate H+ (protons) in solution, and makes pH lower (i.e HCl)

Bronsted Lowry base: any species that will accept H+ (protons) in solution, and makes pH higher (NH3 will accept H+ to form NH4+)

Typically, acid/bases are shown in the left (reactants)

when we write the products:

Bronsted Lowery conjugate base = the base formed when the B.L. acid donates its H+ proton ( i.e. HCl -> Cl-

Bronsted Lowery conjugate acid = the acid formed when the B.L. base accept its H+ proton ( i.e. NH4+ has accept H+ proton)

Note that, typically conjugate bases/acids are shown in the right (product) side

So, from your reaction:

NO2-(aq) + H2O(l) = HNO2(aq) + OH-(aq)

the equilbirium lies to the left, NO2- will be present mostly as an ion

some NO2- will form HNO2 due to hydrolysis, but this is less than 5-10% of the ionizaiton

therefore

reactatns, NO2-(aq) + H2O(l) = are favoured