AB3---->A+³ + 3B¯
if conc of 1 mole AB3 is C, thn after dissociation, conc will be C-C$ of AB3, C$ of A+³ nd 3C$ for three moles of B¯..

Weak Electrolytes and Concentration of the Anion

A weak electrolyte is a substance that only partially dissociates into ions when dissolved in water. The degree of dissociation is represented by the term alpha (α), which signifies the fraction of the compound that ionizes.

The concentration of the anion in a weak electrolyte solution is directly related to the degree of dissociation. The higher the degree of dissociation, the greater the concentration of the anion.

Let's consider the different options and determine the correct one based on the given information.

A) AB2
In this case, the weak electrolyte AB2 can dissociate into two anions (B-) and one cation (A2+). The degree of dissociation (α) represents the fraction of AB2 that ionizes. Therefore, the concentration of the anion is equal to 2cα, where c represents the initial concentration of the weak electrolyte.

B) AB
For the weak electrolyte AB, the dissociation equation would yield one anion (B-) and one cation (A+). The concentration of the anion would be equal to cα.

C) AB3
For AB3, the dissociation equation would yield three anions (B-) and one cation (A3+). The concentration of the anion can be calculated as 3cα.

D) A3Br
In this case, the compound A3Br is not mentioned as a weak electrolyte. Therefore, we cannot determine the concentration of the anion based on the given information.

Based on the given options, the correct answer is option C) AB3, which has a concentration of the anion equal to 3cα.

To summarize:
- The concentration of the anion in a weak electrolyte solution depends on the degree of dissociation (α).
- For AB2, the concentration of the anion is 2cα.
- For AB, the concentration of the anion is cα.
- For AB3, the concentration of the anion is 3cα.
- A3Br is not mentioned as a weak electrolyte, so we cannot determine the concentration of the anion for this compound.