Electrical Properties of Colloids

Q. Colloidal particles tend to be electrically charged and when they are dispersed through a liquid dispersion medium, they tend to attract oppositely-charged counter ions or dipoles to their vicinity from the dispersion medium. The parallel layers of charge surrounding the dispersed phase particles is called:

1. Double layer
2. Electric double layer
3. Helmholtz Double layer
4. Electrokinetic potential
5. Zeta potential

Q. Zeta potential (or electro kinetic potential) is the

1. potential required to bring about coagulation of a colloidal sol
2. potential required to give the particles a speed of 1cm/sec in the sol
3. potential difference between fixed charged layer and the diffused layer having opposite charge
4. potential energy of the colloidal particles

Q.

The charge on sol is due to the adsorbed

[MP PMT 1985]

1. 
2. 
3. 
4. 

Q. During the electro-osmosis of $Fe(OH{)}_3$ sol:

1. The sol particles would move towards the anode
2. The sol particles would move towards the cathode
3. The dispersion medium moves towards the anode
4. The dispersion medium moves towards the cathode

Q. How many of the following are negatively charged sols?
$Pt,Au,Ag,Fe(OH{)}_3,Al(OH{)}_3$,
$A{s}_2{S}_3,starch,clay,H_{4}Si{O}_4,eosin$,
$methyleneblue,Haemoglobin,Cu,CdS$,
$Congored,Cr(OH{)}_3$

Q. Under the influence of an electric field, the particles in a sol migrate towards the cathode. The coagulation of the same sol is studied using $NaCl,N{a}_{2}S{O}_4$ and $N{a}_{3}P{O}_4$ solutions. The coagulating values will be highest for:

1. $NaCl$
2. $N{a}_{2}S{O}_4$
3. $N{a}_{3}P{O}_4$
4. Same for all

Q. The origin of charge on colloidal solutions is due to:

1. Frictional rubbing
2. Electron capture during Bredig’s arc method
3. Selective adsorption of ion on their surface
4. Addition of protective colloids

Q. Colloidal particles tend to be electrically charged and when they are dispersed through a liquid dispersion medium, they tend to attract oppositely-charged counter ions or dipoles to their vicinity from the dispersion medium. The parallel layers of charge surrounding the dispersed phase particles is called:

1. Double layer
2. Electric double layer
3. Helmholtz Double layer
4. Electrokinetic potential
5. Zeta potential

Q.

Which one of the following is not represented by sols [MP PMT 1992]

1. Absorption

2. Tyndall effect

3. Flocculation

4. Paramagnetism

Q.

Measuring zeta potential is useful in determining a liquid's

1. Viscousity

2. Stability

3. Solubility

4. Particle size