Question

Which of the following colloids are formed when hydrogen sulphide gas is passed through a cold solution of arsenious oxide.

• A. $A s _ { 2 } S _ { 3 }$
• B.
• C. $A s _ { 2 } S$
• D.

Answer 1

Answer: (A)

$A s _ { 2 } S _ { 3 }$

Answer 2

It is due to adsorption of $S ^ { 2 - }$ ions on the surface of the colloidal particles and $H ^ { + }$ ions in the diffused layer.