Question

Which of the carbonates given below is unstable in air and is kept in the $C{O}_2$ atmosphere to avoid decomposition.

• A. $CaC{O}_3$
• B. $BaC{O}_3$
• C. $BeC{O}_3$
• D. $MgC{O}_3$

Answer 1

The correct option is C $BeC{O}_3$

$B{e}^2$ + is the smallest in size among the rest of the alkaline earth metal ions. The
thermol stablilty of a metal carbonate depends
Anion in each of the options is the same that is carbonate ion

${C{O}_3^2}^{-}$

Beryllium carbonate readily decomposes due
to the smaller size of cation and larger size of
anion (as smaller cation stabilizes maller
anion through crystal lattice energy) and
can be kept only in the atmosphere of
$C{O}_2$.


$BeC{O}_3$ decomposes to form BeO and$C{O}_2$