Question

Why NH₄Cl is added before NH₄OH for the ppt. of Fe³⁺ ions? 

(1) To decrease OH^– ion concentration 

(2) To increase Cl^– ion concentration 

(3) To increase \(NH_4^{+}\) ion concentration 

(4) To decrease H⁺ ion concentration

Answer 1

Correct answer is : (1) To decrease OH^– ion concentration

Solid NH₄Cl is added to NH₄OH solution to decrease the OH^– ion concentration due to common ion effect.