Química Geral ⇒ Principais reações inorgânicas- dúvida Tópico resolvido

[Nh3noenem]

É correto afirmar que em toda decomposição de carbonato o ácido sempre vai liberar CO2 + H2O?

[Jigsaw]

É correto afirmar que em toda decomposição de carbonato o ácido sempre vai liberar CO2 + H2O?

Nh3noenem, se for apenas a decomposição do H2CO3 sim, mas em meio aquoso poderá haver formaçao de ânions H3O+, HCO3- e CO3-2:

Carbonic Acid And Carbonate Salts

Carbonic acid (H2CO3) is formed in small amounts when its anhydride, carbon dioxide (CO2), dissolves in water.

CO2 + H2O ⇌ H2CO3

The predominant species are simply loosely hydrated CO2 molecules. Carbonic acid can be considered to be a diprotic acid from which two series of salts can be formed—namely, hydrogen carbonates, containing HCO3−, and carbonates, containing CO32−.

H2CO3 + H2O ⇌ H3O+ + HCO3−
HCO3− + H2O ⇌ H3O+ + CO32−

However, the acid-base behaviour of carbonic acid depends on the different rates of some of the reactions involved, as well as their dependence on the pH of the system. For example, at a pH of less than 8, the principal reactions and their relative speed are as follows:

CO2 + H2O ⇌ H2CO3 (slow)
H2CO3 + OH− ⇌ HCO3− + H2O (fast)

Above pH 10 the following reactions are important:

CO2 + OH− ⇌ HCO3− (slow)
HCO3− + OH− ⇌ CO32− + H2O (fast)

Between pH values of 8 and 10, all the above equilibrium reactions are significant.

REFERÊNCIAS:

https://www.britannica.com/science/oxya ... ref1000415