When a concentrated solution of an electrolyte is diluted, its specific conductance decreases but its equivalent (or molar) conductance increases.

Quick Scoop: What exactly changes?

Think of two different “kinds” of conductance:

  • Specific conductance (κ) : Conductance of a unit volume of solution (e.g., 1 cm³).
  • Equivalent/molar conductance (Λ) : Conductance due to one gram-equivalent or one mole of electrolyte in solution.

When you dilute:

  • In each unit volume , there are fewer ions, so specific conductance drops.
  • But the ions that are present are more free to move (less inter-ionic attraction, more dissociation especially for weak electrolytes), so equivalent/molar conductance rises.

So, the correct conceptual statement is:

When a concentrated solution of an electrolyte is diluted, its specific conductance decreases and its equivalent (or molar) conductance increases.

If this was an MCQ like:

  • (a) specific conductance increases
  • (b) equivalent conductance decreases
  • (c) specific conductance decreases and equivalent conductance increases
  • (d) both increase

Then the correct option is (c).

Why this happens (short story version)

Imagine a crowded hallway vs. a spacious one:

  • In the crowded hallway (concentrated solution), there are many people (ions) per meter, but they bump into each other and can’t move freely.
  • In the spacious hallway (dilute solution), there are fewer people per meter, but each person can walk faster and straighter.

Translated to electrolyte solutions:

  • Dilution reduces the number of ions per unit volume → specific conductance ↓.
  • Dilution reduces ion–ion interactions and increases dissociation , especially for weak electrolytes → each mole or equivalent of electrolyte conducts better → equivalent/molar conductance ↑.

Mini table: what goes up, what goes down?

Here’s the behavior in simple exam language:

[7][2] [3][10][7]
Quantity Symbol What happens on dilution?
Specific conductance κ Decreases (fewer ions per unit volume).
Equivalent / molar conductance Λ Increases (ions move more freely; more dissociation).

Forum-style recap

Q: When a concentrated solution of an electrolyte is diluted, what changes?
A: Specific conductance decreases, equivalent (or molar) conductance increases. This is the standard result used in electrochemistry questions and MCQs.

TL;DR:
When a concentrated solution of an electrolyte is diluted, specific conductance ↓, equivalent/molar conductance ↑.

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