Which of the following compound/ions is amphoteric? Question 92Select one: a. SO2 b. NH3 c. H2SO4 d. None of the other choices is true e. HCO3-

The term "amphoteric" refers to a substance that can act as both an acid and a base. This means it can either donate or accept a proton (H+ ion).

Let's analyze each option:

a. SO2 - Sulfur dioxide is a nonmetal oxide and typically acts as an acid. It does not have the ability to act as a base, so it is not amphoteric.

b. NH3 - Ammonia can accept a proton to become ammonium (NH4+), acting as a base. However, it does not have a hydrogen that it can easily donate, so it does not act as an acid. Therefore, it is not amphoteric.

c. H2SO4 - Sulfuric acid is a strong acid. It can donate protons but cannot accept them, so it is not amphoteric.

e. HCO3- - The bicarbonate ion can both accept a proton to become carbonic acid (H2CO3) and donate a proton to become the carbonate ion (CO3 2-). Therefore, it is amphoteric.

So, the correct answer is:

e. HCO3-