Question

When hno2 dissociates in water, which atom is dontaing electrons, allowing water to act as a lewis base?

Answer 1

Answer to this is O-atom.

Explanation: The Bronsted acid-base theory is the backbone of chemistry. This theory focuses mainly on acids and bases acting as proton donors or proton acceptors.

$A^+ + B^- \rightarrow A-B$

where $A^+$ is the Lewis Acid and $B^-$ is the Lewis Base and $A-B$ is the Covalent Bond.

Reaction of dissociation of $HNO2$ in $H_2O$ is given as:

$HNO_2 + H_2O \rightarrow H_3O^+ + NO_2^-$

In this reaction O-atom has lone pair in water and therefore it accepts the proton from $HNO_2$ forming a Lewis Base.