Methods to Form Lyophobic Colloids

Q. 14. why is [Ni(NH3)2Cl2] has tetrahedral geometry and why it does not show isomerism?

Q.

What is meant by polar solvent and polar solute with two examples.

Q.

What is the main reason for stability of colloidal solution?

Q. the conductivities at infinite dilution of NH_4Cl, NaOHand NaCl are 130, 218, 120 ohm^{-1}cm^2eq^{-1}.If equivalent conduc†an ce ofN/100 solution of NH_4OH is 10, the degree of dissociation of

Q.

Why do hydrophobic sols get coagulated easily?

Q. 13. convert propan-1-ol to propan-2-ol

Q.

Why is butter a colloid?

Q.

is blood a homogenous mixture ? If yes, then is it present in one phase

Q. Also known as the electro-dispersion method, the Bredig’s arc method applies a high voltage between two electrodes of a metal (like gold or silver) immersed in a dispersion medium to obtain a colloidal sol of the metal. Which of the following regarding the electrodes?

1. The electrodes are made of different metals
2. The electrodes are made of the same metals
3. The electrodes are kept very far apart
4. The electrodes are kept close to each other and the dispersion medium is cooled by a freezing mixture

Q.

Q. If there is 0.1M of AgNO3 and 0.01M of NaCl is there in a container separated by a semi permeable membrane. Will precipitate form ?if not , why ?

Q.

Which method is used for the preparation of metal sols?

Q.

Colloidal solution of arsenious sulphide can be prepared by

[AMU 1985]

1. Peptization

2. Double decomposition

3. Electrodispersion method

4. Hydrolysis]

Q.

What is demulsification? Name two demulsifiers.

Q. When an excess of $AgN{O}_3$ is treated with $KI$ solution, $AgI$ forms a:

1. positively charged sol
2. negatively charged sol
3. neutral sol
4. true solution

Q. Explain geometrical isomerism in cyclohexane in details.

Q. How many resonating structures can be drawn for 2, 4-pentadienyl radical?

Q. Compare (coc) bond angle in diphenyl ether and dimethyl ether

Q.

How many state are in colloidal solution?

1)1

2)2

3)3

4)4

Q.

Which colloids are irreversible?

1. Multimolecular

2. Lyophobic

3. Associated

4. Lyophillic

Q. Why does c-cl bond have higher dipole movement than c-f bond

Q. what is the formulae of pyridinium chlorochromate

Q.

1. True
2. False

Q.

You are provided with a $500mL$ of hard water, containing $0.005mole$ of $CaC{l}_2$, and two sulphuric acid samples of $0.001M$ and $0.02M$ concentrations. The solubility product of calcium sulphate in water at ${25}^{\circ }C$ is $2.4\times {10}^{-5}$. Choose the most appropriate answer:

1. will cause precipitation but sample doesn't

2. Neither will cause precipitation

3. Both samples of will cause precipitation

4. will cause precipitation but sample doesn't

Q. When dilute aqueous solution of $AgN{O}_3$ (excess) is added to $KI$ solution, positively charged sol particles of $AgI$ are formed due to adsorption of ion :

1. $K^{+}$
2. $A{g}^{+}$
3. $I^{-}$
4. $N{O}_3^{-}$

Q. Define peptization.

Q.

Lyophobic colloids are

Q. What is peptization? Explain.

Q. The Ratio of Fe+3 and fe+2 in Fe0.9S1.0?

Q. Which of the following properties are characteristic of lyophobic sols?
1. Low viscosity; 2. High viscosity; 3. Reversibility and 4. Coagulation by electrolytes at low concentration
Select the correct answer using the codes given below:

1. 2, 3 and 4
2. 2 and 3 only
3. 1 and 4 only
4. 1 and 3 only

Q. Which one of the following processes does not involve coagulation?

1. Tanning of leather using tannin
2. Peptization
3. Formation of delta
4. Purification of drinking water using alum