Is Sodium bicharbonate NaHCo^3 (aq) is salt or base or acid or neither? which is it?

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valentin68 | College Teacher | (Level 3) Associate Educator

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Sodium bicarbonate (baking soda) `NaHCO_3` (s) is an acidic salt.

It is a salt because it contains the functional group `-HCO_3` tied to a `Na` (or metallic) atom. The functional group `-HCO_3` comes from the weak acid `H_2CO_3` by loosing only one atom of `H` . Because of this the functional group `-HCO_3` although not a complete acid (because it lacks one atom of `H` ) still has some acidic character.

When dissolved in water the functional group `HCO_3^-` transforms into a a proper acid

`HCO3^(-) +H_2O =H_2CO3 +OH^-`

Thus of the presence of `OH^-` (which is a stronger base than the weak acid `H_2CO_3` ) functional group, the aqueous solution of `NaHCO_3` (aq) is a bit basic.

Answer: `NaHCO_3` (s) is an acidic salt and `NaHCO_3 (aq)` is a bit basic.