Question

Is ${\mathrm{CO}}_2$ an acid or a base?

Answer 1

Lewis acids and base:

1. Lewis acids are chemical compounds with vacant orbitals that can accept electron pairs from Lewis bases.
2. Some common examples: Iron (${\mathrm{Fe}}^{+2}$and ${\mathrm{Fe}}^{+3}$), Cations of d-block elements that represent high-oxidation states Copper ($\mathrm{Cu}$), Hydroium ions (${\mathrm{H}}_2{\mathrm{O}}^{+}$) ,hydrogen ions, and Metal cations such as ${\mathrm{Li}}^{+}$ and${\mathrm{Mg}}^{+2}$.
3. A Lewis base is a species that possesses a single pair of electrons and can donate an electron pair.
4. ${\mathrm{H}}_2\mathrm{O},{\mathrm{Cl}}^{-},{\mathrm{I}}^{-},{{\mathrm{CH}}_3}^{-},{{\mathrm{NH}}_3}^{-}$are some examples of lewis base.
5. Carbon dioxide is a polar molecule that has a positive center on the carbon atom and can attract (and accept) lone electron pairs. found on the Oxide ion (${{\mathrm{O}}_2}^{-}$).
6. As a result, Carbon dioxide acts as a Lewis acid, whereas the Oxide ion acts as a Lewis base.
7. When Carbon dioxide is dissolved in water to generate Carbonic acid, the water acts as a Lewis base, donating electron pairs while Carbon dioxide takes them.

Therefore, Carbon dioxide is a lewis acid.