Question

Which term of molar conductivity is used when the concentration of electrolyte approaches zero?

• A. Infinite molar conductivity
• B. Zero molar conductivity
• C. Standard molar conductivity
• D. Limiting molar conductivity

Answer 1

The Correct Option is D

When discussing the properties of electrolytes, we often refer to molar conductivity, denoted by the symbol Λ_m. This term describes how well an electrolyte conducts electricity when dissolved in a solution, and it depends on the concentration of the electrolyte. As the concentration decreases, molar conductivity typically increases due to reduced ion pairing.

Molar conductivity at zero concentration is particularly significant, which is the behavior of the electrolyte when dilution approaches infinity (i.e., when concentration approaches zero). This condition reflects the "limiting molar conductivity" (Λ_mº). It represents the molar conductivity of an electrolyte solution at infinite dilution, where interactions between ions are minimized.

Thus, the term used when the concentration of electrolyte approaches zero is: Limiting molar conductivity.

Answer 2

The term used when the concentration of an electrolyte approaches zero, referring to its molar conductivity, is known as "limiting molar conductivity." This term is significant in chemistry when discussing how ionic conductance behaves at infinite dilution. At this point, ions are assumed to be sufficiently far apart so they don't interact with each other, allowing the conductance to be measured without interference. 

Explanation:

• Molar Conductivity (Λ_m): It's defined as the conductivity of an electrolyte solution divided by its molar concentration.
• As the concentration of an electrolyte decreases, the molar conductivity increases because ions move more freely with less hindrance from other ions.
• Limiting Molar Conductivity (Λ_m⁰): This is the value of molar conductivity at infinite dilution, meaning the concentration approaches zero.
• Therefore, at zero concentration, the interference between ions is negligible, allowing each ion to contribute maximally to conductivity.