Question

Assertion: Coagulation power of $A{l}^{3+}$ is more than $N{a}^{+}$

Reason : Greater the valency of the flocculating ion added, greater is its power to cause precipitation (Hardy Schulze rule).

• A. Assertion and reason both are correct and the reason is the correct explanation of assertion
• B. Both assertion and reason are incorrect.
• C. Assertion is incorrect but reason is correct.
• D. Assertion is correct but reason is incorrect.
• E. Assertion and reason both are correct but reason does not explain assertion

Answer 1

The correct option is A Assertion and reason both are correct and the reason is the correct explanation of assertion

According to Hardy Schulze rule

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Coagulating power of an electrolyte is directly proportional to the valency of the active ions.

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The ions which are carrying the charge opposite to that of sol particles are effective in causing coagulation of the sol.

So, we get to know that the greater the valency of the active ion or flocculating ion, the greater will be its coagulating power.

The coagulation capacity depends upon the valency of the active ion as well and is called a flocculating ion.

As the valency of $Al\text{is}3$ which is more than $Na$ whose valency is $1$, the coagulating power of $A{l}^{3+}$ is more than $N{a}^{+}$.

Hence, Assertion and reason both are correct and the reason is the correct explanation of assertion