Question

A solution containing CaCl is mixed with a solution of LICO, to form a solution that is 2.1 x 10 Min calcium ion and 4.75 x 10 Min Oxalate lon. What will happen once these solutions are mbed? Kp (Cac 04) - 23 x 10 Nothing will happen since calcium oxalate is extremely soluble . Nothing will happen sinco Kup > Q for all possible precipitants. A precipitate will form since Q> Kop for calcium oxalate. Nothing will happen since both calcium chloride and lithium oxalate are soluble compounds. There is not enough information to determine

Answer 1

Ans :- Option (b) " Nothing will happen since K_sp > Q_sp for all possible precipitants " is the correct answer.

Explanation :-

Calcium oxalate (CaC₂O₄) is the sparingly soluble salt which partially dissociated into its ions in aqueous solution as :

CaC₂O₄ (s) <----------------------> Ca²⁺ (aq) + C₂O₄^2- (aq)

Given,

Concentration of Calcium ion (Ca²⁺) at any time (say t) of the reaction is = [Ca²⁺]_t = 2.1 x 10^-5 M and

Concentration of oxalate ion (C₂O₄^2-) at any time (say t) of the reaction is = [C₂O₄^2-]_t = 4.75 x 10^-5 M

Solubility Product of salt (Ksp) is " The product of the molar concentration of products raised to the power of stoichiometric coefficients with respect to each product species at equilibrium stage of the reaction. Ionic Product of salt (Qsp) is " The product of the molar concentration of products raised to the power of stoichiometric coefficients with respect to each product species at any stage of the reaction.

Now, The expression of Q_sp for CaC₂O₄ salt is :

Q_sp = [Ca²⁺]_t.[C₂O₄^2-]_t

Substitute the values of [Ca²⁺]_t and[C₂O₄^2-]_t in this equation :

Q_sp = (2.1 x 10^-5 M).(4.75 x 10^-5 M)

Q_sp = 9.975 x 10^-10 M²

Because, K_sp ( Given, 2.3 x 10^-9) > Q_sp (9.975 x 10^-10 ), Therefore sparingly soluble salt Calcium oxalate (CaC₂O₄) do not form precipitates as the equilibrium will shift in the forward direction where solubility of Calcium oxalate (CaC₂O₄) increases.

Hence, Option (b) " Nothing will happen since K_sp > Q_sp for all possible precipitants " is the correct answer.