Question

Assertion :Colloidal sol $Fe{\left(OH\right)}_3$ formed by peptization carries positive charge. Reason: During the formation of positively charged colloidal particles of $Fe{\left(OH\right)}_3$, the electrons are lost by the colloidal particles of $Fe{\left(OH\right)}_3$.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Assertion is incorrect but Reason is correct

Answer 1

The correct option is C Assertion is correct but Reason is incorrect

Peptization takes place forming a positively charged colloidal sol of $Fe(OH{)}_3$. Peptization is a process of passing of a precipitate into colloidal particles by adding suitable electrolyte.

A reddish brown colored colloidal solution is obtained by adding the small quantity of ferric chloride solution to the freshly precipitated ferric hydroxide.

$Fe(OH{)}_3$ have a tendency to adsorb preferentially the $F{e}^{3+}$ ions present in the solution as $F{e}^{3+}$ ions are common to the lattice of $Fe(OH{)}_3$ particle which impart positive charge to the colloidal particles present in the solution.