Infinite Dilution

Infinite dilution refers to a condition in which a solute is dissolved in a solvent to such a low concentration that interionic effects between the solute particles are negligible. This condition is commonly observed in solutions of weak electrolytes, where the degree of ionization is low. Let's understand each option in detail:

a) 1 for weak electrolytes
In the case of weak electrolytes, only a small fraction of the solute molecules dissociate into ions when dissolved in a solvent. The degree of ionization, represented by the symbol α, is the ratio of the number of ions formed to the total number of molecules present in the solution. At infinite dilution, the degree of ionization approaches 1, meaning that almost all the solute molecules dissociate into ions.

b) An electrolyte is 100% dissociated
When an electrolyte is 100% dissociated, it means that all the solute molecules have broken apart into ions in the solvent. This condition is typically observed in strong electrolytes, such as strong acids or bases, which completely ionize in solution. However, in the context of infinite dilution, weak electrolytes are considered, and they do not reach 100% dissociation even at infinite dilution.

c) All interionic effects disappear
Interionic effects arise due to the interactions between ions in a solution. These effects can include ion-ion attractions or repulsions, ion-dipole interactions, or ion-solvent interactions. At infinite dilution, the concentration of ions is extremely low, leading to a decrease in interionic interactions. As a result, the interionic effects become negligible, and the solution behaves as if there are no interactions between the ions.

d) All of the above
Option D, "All of the above," is the correct answer because all three statements (a, b, and c) are true. Infinite dilution is a condition where weak electrolytes approach full ionization (option a), strong electrolytes are fully dissociated (option b), and interionic effects become negligible (option c). Thus, option d encompasses all these aspects of infinite dilution.

Overall, infinite dilution is a concept that describes the behavior of solutes at extremely low concentrations, where the effects of ionization and interionic interactions become minimal. It is an important concept in the study of electrolyte solutions and their behavior.