Consider the following statements related to colloids.
(I) Lyophobic colloids are not formed by simple mixing of dispersed phase and dispersion medium.
(II) For emulsions, both the dispersed phase and the dispersion medium are liquid.
(III) Micelles are produced by dissolving a surfactant in any solvent at any temperature.
(IV) Tyndall effect can be observed from a colloidal solution with dispersed phase having the same refractive index as that of the dispersion medium.
The option with the correct set of statements is
Consider the following statements related to colloids.
(I) Lyophobic colloids are not formed by simple mixing of dispersed phase and dispersion medium.
(II) For emulsions, both the dispersed phase and the dispersion medium are liquid.
(III) Micelles are produced by dissolving a surfactant in any solvent at any temperature.
(IV) Tyndall effect can be observed from a colloidal solution with dispersed phase having the same refractive index as that of the dispersion medium.
The option with the correct set of statements is
- (I) and (II)
- (II) and (III)
- (III) and (IV)
- (II) and (IV)
The Correct Option is A
Solution and Explanation
The correct set of statements related to colloids is:
(I) Lyophobic colloids are not formed by simple mixing of dispersed phase and dispersion medium.
(III) Micelles are produced by dissolving a surfactant in any solvent at any temperature.
Therefore, the correct option is (A) (I) and (II).
Lyophobic colloids cannot be produced by merely combining the dispersed phase and dispersion medium through basic mixing. The formation of their colloidal solutions necessitates the utilization of distinct techniques. Emulsions represent colloidal systems comprising a liquid dispersed phase within a liquid dispersion medium. Micelle formation takes place when the temperature surpasses a specific threshold called the Kraft temperature (TK) and when the concentration surpasses a distinct threshold known as the critical micelle concentration (CMC). The Tyndall effect becomes noticeable when there is a substantial discrepancy in the refractive indices between the dispersed phase and the dispersion medium.
Top Questions on Colloids
- Which of the following is an emulsion?
- The gold number range of some lyophilic colloids is given below: A: 0.005–0.01, B: 0.15–0.25, C: 0.04–1.0, D: 15–25
- Which of the following sols are correctly matched with their corresponding charges?
(A) Cr(OH)3 sol: negatively changes sol
(B) TiO2 sol: positively charges sol
(C) CdS sol : positively charged sol
(D) Gum : negatively sol
(E) Silver sol : positively charged sol
Choose the correct answer from the option given below - Coagulating power of an ion for a colloid solution depends on
- Which of the following statements are true?
A. Flocculation value is inversely proportional to the coagulating power.
B. Colloidal silicon is a protective colloid.
C. Alum is used for cleaning muddy water.
D. Gelatin is added to ice cream to act as an emulsifier.
Choose the most appropriate answer from the options given below.
Concepts Used:
Colloids
A colloid is a mixture in which one substance consisting of microscopically dispersed insoluble particles is suspended throughout another substance. Some definitions specify that the particles must be dispersed in a liquid, while others extend the definition to include substances like aerosols and gels.
Example of Colloids:
- Blood: A respiration pigment which has albumin protein in water. Pigment part contains albumin that acts as the dispersed phase and the dispersion medium is water. It is a hydrosol.
- Cloud: It contains air which is the dispersion medium and droplets of water as a dispersed phase. These are aerosol.
- Gold sol: It is a metallic sol in which gold particles are dispersed in the water.
Read More: Classification of Colloids
Property of Colloid Particles:
- Colloids are insoluble particle mixes (sometimes known as colloidal solutions or colloidal systems). They depict the microscopic dispersion of one substance as well as a suspension in another substance. In a colloid, the size of these suspended particles can range from 1 to 1000 nanometres (10-9 meters). They are heterogeneous in nature.
- Colloidal dispersions are made up of particles that are substantially larger than conventional solution solutes. Colloidal particles are large molecules or clusters of smaller species that scatter light.
Purification of Colloids:
Colloids contain ionic impurities and other categories of impure substances that decrease the quality of colloids used in various applications. Following are the methods to purify the colloids.