JIPMER2015ChemistrySurface Chemistry
In an experiment, addition of 4.0 mL of 0.005 M BaCl ₂ to 16.0 mL of arsenious sulphide sol just causes complete coagulation in 2 h . The flocculating value of the effective ion is
Options
- ABa ²⁺, 1.0
- BBa ²⁺, 2.0
- CCl ⁻, 1.0
- DCl ⁻, 2.0
Correct answer
A. Ba ²⁺, 1.0
Step-by-step solution
As ₂ ~S ₃ sol is negatively charged owing to preferential adsorption of S ²⁻ ions. Cation would be effective in causing coagulation. Flocculating value = minimum millimole of the effective ion per litre of sol = 4 0.005 (4+16) 10⁻³ =1.0