# Is NaHCO₃ a carbonate?

I know that $\ce{NaHCO3}$ is sodium bicarbonate, but According to Wikipedia:

In chemistry, a carbonate is a salt of carbonic acid, characterized by the presence of the carbonate ion, $\ce{CO3^{2-}}$.

$\ce{NaHCO3}$ also has the $\ce{CO3^{2-}}$ group, but is it a carbonate?

That is, are bicarbonates a subset of carbonates?

Carbonates are salts and esters of carbonic acid $\ce{H2CO3}$.

In generic nomenclature you may therefore consider a hydrogen carbonate also a subset of all carbonates. They are sometimes also referred to as primary carbonates.

Another considerable point is, that the structural subunit $\ce{O=C(-O-)2}$is still conserved.

In a stricter sense a hydrogencarbonate is only all forms involving $\ce{HCO3-}$, so it appears to be not a generic carbonate, but a class of its own. This refers to its one $\ce{O-H }$ bond and therefore it being a different structure.

However, another point of view should always consider aqueous solution equilibrium. \begin{aligned} \ce{HCO3- + H2O &<=> H3+O + \color{\red}{CO3^{2-}}}\\ \ce{HCO3- + H2O &<=> H2CO3 + {}^{-}OH} \end{aligned}

You can see that carbonate ions will be present to a certain extend in solution. The chemistry will therefore also to some extend resemble the chemistry of the carbonate.

Chemical properties of bicarbonate compound might differ from the pure carbonates - incorporation of water, solubility, ... .

On another page, in organic chemistry the compound class carbonates refers to structures of the type $\ce{\color{\red}{R}-{CO3}-\color{\navy}{R'}}$, where $\ce{\color{\red}{R},\color{\navy}{R'}$\in$Alkyl, Aryl}$ - hence esters.

To sum it all up, since a more stringent definition of carbonate is not present to me, I would always consider a bicarbonate a carbonate.

I would consider it a carbonate. Chemistry of sodium bicarbonate, or sodium hydrogen carbonate, or simply baking soda, is very similar to that of just sodium carbonate, or $\ce{Na_2CO_3}$.

Adding a strong acid to either $\ce{Na_2CO_3}$ or $\ce{NaHCO_3}$ will effect bubbling. Why? The acid protonates the carbonate or bicarbonate and forms the unstable $\ce{H_2CO_3}$, which is generally referred to as carbonic acid, but is in fact a mixture of carbonic acid and the much less potent acid, hydrated carbon dioxide. $\ce{H_2CO_3}$ decomposes rapidly to water and carbon dioxide. Hence, in the lab, if you wished to test for the present of carbonate in a salt, you could try adding a strong acid and look for bubbling. Copious bubbling is an indication of the presence of a carbonate or a carbonate derivative such as $\ce{HOCO_2^-}$ ($\ce{HCO3^-}$). To verify which carbonate you may simply perform a pH test as the $\ce{CO_3^2-}$ anion is a much strong base than the $\ce{HOCO_2^-}$ ion.