Electrical Properties of Colloids

Q. The coagulation of $10{\text{cm}}^3$ of Gold sol by 1 mL $10\%$ NaCl solution is completely prevented by addition of $0.25\text{g}$ of starch to it. The gold number of starch is:

Q. Which of the following statement about zeolite is false?

1. Some of the SiO₄^4- units are repalced by AlO₄^5- and AlO₆^9- ions in zeolite
2. They have open structure which enables them to take up small molecules
3. Zeolites are aluminosilicates having three dimensional network
4. They are used as cation exchangers

Q.

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

1. Tyndall effect

2. Flocculation

3. Paramagnetism

4. Absorption

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

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

Q. When an excess of a very dilute aqueous solution of KI is added to a very dilute aqueous solution of silver nitrate, the colloidal particles of silver iodide are associated with which of the following Helmholtz double layer?

1. AgI ¦ Ag⁺ ¦ I^-
2. AgI ¦ K⁺ ¦ NO₃^-
3. AgI ¦ NO₃^- ¦ K⁺
4. AgI ¦ I^- ¦ K⁺

Q. Zeta potential ( or electrokinetic potential ) is the

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

Q.

When excess of $AgN{O}_3$ is treated with KI solution, AgI forms

1. +ve charged sol
2. -vely charged sol
3. neutral sol
4. neutral sol

Q.

The charge on sol is due to the adsorbed

[MP PMT 1985]

1. 
2. 
3. 
4. 

Q. When a small amount of an electrolyte is added to a colloidal dispersion, the dispersed phase particles are surrounded by either the anions or the cations. This is because:

1. The colloidal particles tend to selectively adsorb either positively or negatively charged ions
2. The ions of the electrolyte remove protons from the dispersion medium
3. The ions of the electrolyte remove electrons from the dispersion medium
4. Of Hydrogen bonding

Q.

When an excess of a very dilute aqueous solution of KI is added to a very dilute aqueous solution of silver nitrate, the colloidal particles of silver iodide are associated with which of the following Helmholtz double layer?

1. AgI ⋮ Ag⁺ ⋮ I^–
2. AgI ⋮ K⁺ NO₃^-
3. AgI ⋮ NO₃^- ⋮ K⁺
4. AgI ⋮ I^– ⋮ K⁺