Experts please answer...

Dear student,

The correct answer is option (d)  i.e. Al2O3.xH2O : negatively charged sol is an incorrect match

Colloidal particles always carry an electric charge. For a given colloidal solution nature of the charge is same on all the particles.
The origin of charge on the sol particles is due to the preferential adsorption of either positive or negative ions on their surface.
There can be different ways to acquire electric charge by the sol particles, some colloidal particles develop charge due to ionisation or dissociation of surface charge. sometimes frictional electrification due to rubbing of dispersed phase with that of dispersion medium may result in some charge on the colloidal particles also.

Charge on the given colloids are as follows:
CdS is a negatively charged sol
Charcoal is a negatively charged sol
Metallic oxides like TiO2 are positively charged sol
Hydrated metallic oxides like Al2O3.xH2O are positively charged sol

Regards
 

  • 0
What are you looking for?