Question

The following compounds have been arranged in order of their increasing thermal stabilities. Identify the correct order :
(I) $K_{2}C{O}_3$
(II) $MgC{O}_3$
(III) $CaC{O}_3$
(IV) $BeC{O}_3$

• A. $I<II<III<IV$
• B. $IV<II<III<I$
• C. $IV<II<I<III$
• D. $II<IV<III<I$

Answer 1

The correct option is B $IV<II<III<I$

The stability of carbonates increases with the increasing electropositive character of the metal.

Hence, the correct increasing order for thermal stabilities is $IV<II<III<I$.

It can also be written as $BeC{O}_3<MgC{O}_3<CaC{O}_3<K_{2}C{O}_3$