If one ion of a sparingly soluble salt is externally added to its solution, what will happen?
Answer and explanation
Correct answer: Solubility of the salt will decrease
Adding an ion already produced by the dissolving salt creates the common-ion effect. For MX(s) ⇌ M+ + X−, adding M+ or X− raises the ionic product and shifts the equilibrium toward solid MX. Consequently, the amount of salt that can remain dissolved decreases; some may precipitate. Evaporation of the salt or disappearance of solvent is unrelated to this equilibrium effect.
Frequently asked questions
What is the correct answer to this question?
Solubility of the salt will decrease
Why is this the correct answer?
Adding an ion already produced by the dissolving salt creates the common-ion effect. For MX(s) ⇌ M+ + X−, adding M+ or X− raises the ionic product and shifts the equilibrium toward solid MX. Consequently, the amount of salt that can remain dissolved decreases; some may precipitate. Evaporation of the salt or disappearance of solvent is unrelated to this equilibrium effect.
Which subject and chapter does this question cover?
This is a Class 11 Chemistry question. Chapter: Equilibrium. Topic: Solubility product and common ion effect.
