Ncert Exercises & Solutions

Metal carbonates decompose on heating to give metal oxide and carbon dioxide. Which of the metal carbonates is most stable thermally?

1. ${MgCO}_{3}$

2. ${CaCO}_{3}$

3. ${SrCO}_{3}$

4. ${BaCO}_{3}$

Hint: Down the group thermal stability increases

{BaCO}_{3}

thermally most stable because thermal stability increases with increasing cationic size.

{Ba}^{2 +}

cation has the maximum size among all given cations, that is,

{Mg}^{2 +}, {Ca}^{2 +} and {Sr}^{2 +}