Question

Which molecule is amphoteric? A) NH4+ B )H2O C )H2CO3− D )H2SO4

Answer 1

Answer: B ) $H_2O]$

Explanation:- According to the Bronsted Lowry conjugate acid-base theory, an acid is defined as a substance which donates protons and a base is defined as a substance which accepts protons.

Amphoteric substances are substances which can act as both acids and bases and thus can accept and donate $H^+$ ions.

$H_2O\rightarrow H^++OH^_$

Here water acts as an acid as it donates $H^+$ ions.

$H_2O+H^+\rightarrow H_3O^+$

Here water acts as a base as it accepts $H^+$ ions.

Answer 2

The answer is letter choice B