JEE Main 2020
LEVELJEE Main
Visualized Solution
The Sigma Insight: Colloids, Micelles and and Emulsions
The Magic of Micelles
Have you ever wondered how soap cleans away grease? The secret lies in tiny structures called micelles.
Imagine a molecule with a split personality. One end loves water (hydrophilic), and the other end hates it (hydrophobic). When you drop these molecules into water, they face a dilemma. The water-loving heads are perfectly happy, but the water-hating tails are desperate to escape.
To solve this, they huddle together! The hydrophobic tails hide in the center, forming a tiny, oil-like droplet, while the hydrophilic heads form a protective shield on the outside, interacting with the water. This spherical structure is a micelle.
Analyzing the Suspects
Let's look at our options to see which one can pull off this trick.
Option (a) presents a molecule with an imidazolium ring and methyl groups. This part is bulky and hydrophobic. It also has a sulfate ion (), which is highly hydrophilic. This classic amphiphilic structure is perfect for forming an ionic micelle in water.
Option (b) suggests mixing liquid diethyl ether with an aqueous NaCl solution. This is just mixing two liquids; no surfactant molecules are present to form micelles.
Option (c) involves sodium stearate in pure toluene. Toluene is a non-polar solvent. In such solvents, surfactants form reverse micelles, where the hydrophilic heads hide in the center and the hydrophobic tails point outwards. This isn't the typical ionic micelle formed in water.
Option (d) is similar to (a) but has a hexafluorophosphate ion (). This ion is much less hydrophilic than sulfate, making it less effective at forming stable micelles in water.
The Verdict
Therefore, the compound in Option (a) is the clear winner, possessing the right balance of hydrophobic and hydrophilic character to form an ionic micelle.
Similar Questions
JEE Advanced 2023
LEVELJEE Main
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
(A)
(I) and (II)
(B)
(II) and (III)
(C)
(III) and (IV)
(D)
(II) and (IV)
JEE Main 2021
LEVELJEE Main
The sol given below with negatively charged colloidal particles is
(A)
added to hot water
(B)
added to solution
(C)
added to solution
(D)
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JEE Advanced 2019
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Molar conductivity () of aqueous solution of sodium stearate, which behaves as a strong electrolyte, is recorded at varying concentration(c) of sodium stearate. Which one of the following plots provides the correct representation of micelle formation in the solution? (Critical micelle concentration (CMC) is marked with an arrow in the figures.)
(A)
(B)
(C)
(D)
JEE Advanced 2021
LEVELJEE Main
The correct statement(s) related to colloids is(are)
* Multiple Correct Options
(A)
The process of precipitating colloidal sol by an electrolyte is called peptization.
(B)
Colloidal solution freezes at higher temperature than the true solution at the same concentration.
(C)
Surfactants form micelle above critical micelle concentration (CMC). CMC depends on temperature
(D)
Micelles are macromolecular colloids.
JEE Main 2020
LEVELJEE Main
Match the following:\\ \begin{array}{ll} \text{I. Foam} & \text{(A) Smoke} \\ \text{II. Gel} & \text{(B) Cell fluid} \\ \text{III. Aerosol} & \text{(C) Jellies} \\ \text{IV. Emulsion} & \text{(D) Rubber} \\ & \text{(E) Froth} \\ & \text{(F) Milk} \end{array}
(A)
(I)-(D), (II)-(B), (III)-(A), (IV)-(E)
(B)
(I)-(B), (II)-(C), (III)-(E), (IV)-(D)
(C)
(I)-(E), (II)-(C), (III)-(A), (IV)-(F)
(D)
(I)-(D), (II)-(B), (III)-(E), (IV)-(F)
JEE Main 2021
LEVELJEE Main
Sodium stearate is an anionic surfactant which forms micelles in oil. Choose the correct statement for it from the following. [2021, 22 July Shift-I]
(A)
It forms spherical micelles with group pointing towards the centre of sphere.
(B)
It forms non-spherical micelles with group pointing outwards on the surface.
(C)
It forms spherical micelles with group pointing outwards on the surface of sphere.
(D)
It forms non-spherical micelles with group pointing towards the centre.
JEE Main 2021
LEVELJEE Main
Match List I with List II. \begin{array}{ll} \text{List I} & \text{List II} \\ \text{(A) Cheese} & \text{I. Dispersion of liquid in liquid} \\ \text{(B) Pumice stone} & \text{II. Dispersion of liquid in gas} \\ \text{(C) Hair cream} & \text{III. Dispersion of gas in solid} \\ \text{(D) Cloud} & \text{IV. Dispersion of liquid in solid} \end{array} Choose the most appropriate answer from the options given below.
(A)
A IV, B III, C II, D I
(B)
A IV, B I, C III, D II
(C)
A III, B IV, C I, D II
(D)
A IV, B III, C I, D II
JEE Main 2021
LEVELJEE Main
The nature of charge on resulting colloidal particles when is added to excess of hot water is
(A)
Positive
(B)
Sometimes positive and sometimes negative
(C)
Neutral
(D)
Negative
JEE Main 2021
LEVELBoard
A colloidal system consisting of a gas dispersed in a solid is called a/an
(A)
solid sol
(B)
gel
(C)
aerosol
(D)
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JEE Main 2019
LEVELJEE Main
The correct option among the following is
(A)
colloidal medicines are more effective, because they have small surface area.
(B)
brownian motion in colloidal solution is faster if the viscosity of the solution is very high.
(C)
addition of alum to water makes it unfit for drinking.
(D)
colloidal particles in lyophobic sols can be precipitated by electrophoresis.