Question

Which best demonstrates an example of the common ion effect?

duction
A The compound CuCl is 500 times less soluble in sea water than it is in
pure water.
ту
B Ammonia is produced commercially when an increase in pressure
shifts the equilibrium toward the product.
ompounds
C A lighted splint goes out in air but bursts into flame when plunged into
pure oxygen.
D The decomposition of carbonic acid in water occurs spontaneously
whereas the combination of carbon dioxide and water does not.

Answer 1

Answer: A. The compound CuCl is 500 times less soluble in sea water than it is in pure water.

pure water.

Step-by-step explanation:

Any change in the equilibrium is studied on the basis of Le-Chatelier's principle.

This principle states that if there is any change in a equilibrium reaction, the equilibrium will shift in a direction so as to minimize the effect.

Thus when a common ion is introduced to an equilibrium reaction, the equilibrium will shift in a direction where the concentration of common ion is decreasing.

`CuCl\rightleftharpoons Cu^++Cl^-`

`NaCl\rightarrow Na^++Cl^-`

When common ion such as
`Cl^-` from NaCl in sea water is introduced to an equilibrium reaction, the equilibrium will shift in a direction where the concentration of common ion is decreasing i.e. in the left side and thus solubility of CuCl further decreases.