Question

The equilibrium constant $K _{ C }$ for the following reaction will be
$K _{2} CO _{3}( aq )+ BaSO _{4}( s ) \rightleftharpoons BaCO _{3}( s )+ K _{2} SO _{4}( aq )$

• A. $\frac{\left[ CO _{3}^{2-}\right]}{\left[ SO _{4}^{2-}\right]}$
• B. $\frac{\left[ K _{2} CO _{3}\right]}{\left[ K _{2} SO _{4}\right]}$
• C. $\frac{\left[ BaSO _{4}\right]}{\left[ CO _{3}^{2-}\right]}$
• D. $\frac{\left[ SO _{4}^{2-}\right]}{\left[ CO _{3}^{2-}\right]}$

Answer 1

Answer: (D)

For the reaction,
$ K _{ c }=\frac{\left[ BaCO _{3}\right]\left[ K _{2} SO _{4}\right]}{\left[ K _{2} CO _{3}\right]\left[ BaSO _{4}\right]} $
$\because\left[ BaCO _{3}( s )\right]=1 $
${\left[ BaSO _{4}( s )\right]=1} $
$\Rightarrow K _{ c }=\frac{\left[ K _{2} SO _{4}\right]}{\left[ K _{2} CO _{3}\right]}$
$\therefore $ Both $K _{2} SO _{4}$ and $K _{2} SO _{3}$ are strong electrolytes
$\therefore K _{ c }=\frac{\left[ SO _{4}^{2-}\right]}{\left[ CO _{3}^{2-}\right]}$