The molar conductivity for electrolytes A and B are plotted against C^(3 / 2) as shown below. Electrolytes A and B respectively are:

Solution

Chemistry ma’am · 3 steps

Look at the shape: a straight line against √C means strong, a sharp shoot-up on dilution means weak.

1. Strong electrolyte. A strong electrolyte is fully ionised at every concentration. Λₘ falls only a little as C rises, because ions drag on each other more. That fall is linear in √C (the x-axis of the graph).

   Λₘ = Λₘ° - A√C

2. Weak electrolyte. A weak electrolyte ionises more and more as it is diluted. So Λₘ stays low at higher concentration and rises very steeply as C → 0. The plot is a curve, not a line.

   Plot	Shape on the graph	Electrolyte
   A	Curve, rises sharply near C = 0	weak
   B	Straight line, gentle downward slope	strong

3. So. A is a weak electrolyte and B is a strong electrolyte, which is option (b).

The idea to keep. In a Λₘ vs √C plot, a straight line you can extend back to the y-axis means strong. A steep curve that cannot be extended to give Λₘ° means weak.

Answer from the NTA final answer key. Solution by PrepWiser.