What is the process by which one ion is displaced by another called?

What is the process by which one ion is displaced by another called?

• A. Adsorption
• B. Ion Exchange
• C. Electrolysis
• D. Distillation

Answer: (B)

The main idea is that ions in a solution can swap with ions that are bound to a solid that carries fixed charged sites. This swapping is called ion exchange. When a solution containing a given ion meets an ion-exchange material, the incoming ion displaces the ion already held on the solid, replacing it in the solid and releasing the displaced ion into the solution. A common example is water softening: calcium and magnesium ions in the water swap places with sodium ions attached to the resin, so the hard ions enter the resin while sodium ions go into the water. This differs from adsorption, where substances just stick to a surface, and from electrolysis or distillation, which are about electrical decomposition and separation by boiling, respectively.

The main idea is that ions in a solution can swap with ions that are bound to a solid that carries fixed charged sites. This swapping is called ion exchange. When a solution containing a given ion meets an ion-exchange material, the incoming ion displaces the ion already held on the solid, replacing it in the solid and releasing the displaced ion into the solution. A common example is water softening: calcium and magnesium ions in the water swap places with sodium ions attached to the resin, so the hard ions enter the resin while sodium ions go into the water. This differs from adsorption, where substances just stick to a surface, and from electrolysis or distillation, which are about electrical decomposition and separation by boiling, respectively.