Question

Is Sodium bicarbonate NaHCO3 (s) (baking soda) salt or acid or base or neither? which is it?

Answer 1

Sodium bicarbonate is an amphoteric compound. (Amphoteric species is a molecule or ion that can react as an acid as well as a base.)
\[HCO^{−3} + H_2O → H_2CO_3 + OH^−\]
Here you see the bicarbonate gains proton,acting as alkaline or base.
\[H_2CO_3 → H_2O + CO_2\]
Here it acts as an acid, it donates protons forming water and carbon dioxide.