Question

Name a carbonate which does not decompose on heating.​

Answer 1

$\huge\mathbb\fcolorbox{purple}{lavenderblush}{✰Answer}$

A carbonate, which does not decomposes on heating: Sodium Carbonate and Potassium Carbonate.

Answer 2

Sodium carbonate and potassium carbonate is stable and it doesn't decompose by heat. Rest other carbonates decompose on heating.

$\underline{\bf{Explanation\::}}$

As we know that carbonates of alkaline earth

metal i.e. group $(11)$ on heating easily decomposes into carbon dioxide and metal oxide so, as here in magnesium carbonate as Magnesium is present which belongs to group $(11)$ will also decompose when heat will be passed into it.

Hence, we write the reaction as: -

$MgC{O_3}+\Delta \to MgO + C{O_2}$

Thus, it will form its respective metal oxide i.e. magnesium oxide and carbon dioxide will be evolved.

Also $MgC{O_3}$ is a salt of weak acid and a weak base so it can easily be decomposed on heating.

On the other hand we see that as Sodium and Potassium belongs to alkali metals or group $(1)$ metals so the carbonates formed with the alkali group metals will not decompose on heating as they are thermally stable except $L{i_2}C{O_3}$ which is thermally unstable.

Sodium and potassium both are very reactive metals so the carbonates of both the metals are very stable and require a high temperature to decompose into their respective metal oxides and carbon dioxide. In the process of formation of $N{a_2}C{O_3}$ and ${K_2}C{O_3}$, strong bases i.e. $NaOH$ and $KOH$ are used which have the capability to hold carbon dioxide.