Question

Given exothermic reaction
$CoCl _{4}^{2-}+6 H _{2} O _{ (l) } \rightleftharpoons\left[ Co \left( H _{2} O \right)_{6}\right]^{2+}+4 Cl ^{-}$
Which one of the following will decrease the equilibrium concentration of $CoCl _{4}^{2-}$ ?

• A. Addition of $HCl$
• B. Addition of $Co \left( NH _{3}\right)_{2}$
• C. The solution is diluted with water
• D. The temperature is increased

Answer 1

Answer: (C)

Here; water is reactant so increase in concentration of reactant shifts the equilibrium in the forward direction. Hence; on diluting the solution; the equilibrium shifts in the $COCl _{4}^{2-}$