JEE Main · 2022 · 25 Jun 2022 · Shift 1 · Surface Chemistry

Using very little soap while washing clothes, does not serve the purpose of cleaning of clothes because

(A)soap particles remain floating in water as ions
(B)the hydrophobic part of soap is not able to take away grease
(C)the micelles are not formed due to concentration of soap, below its CMC value✓ Correct
(D)colloidal structure of soap in water is completely disturbed.

Answer: (C)

Solution

Soap molecules form micelles in water, which are responsible for the cleaning action. Micelle formation occurs only when the concentration of soap exceeds the Critical Micelle Concentration (CMC). Below the CMC, soap molecules remain dispersed and cannot form micelles, so the cleaning action is ineffective. The correct answer is (C).

JEE Main · 2022 · 25 Jun 2022 · Shift 1 · Single correct option

Practise more: all JEE Main PYQs on Surface Chemistry →

More JEE Main questions on Surface Chemistry

The adsorbent used in adsorption chromatography is/are
A. silica gel
B. alumina
C. quick lime
D. magnesia

Choose the most appropriate answer from the options given below :
JEE Main 2024View solution →
Identity the incorrect pair from the following:
JEE Main 2024View solution →
For the adsorption of hydrogen on platinum, the activation energy is $30 kJ mol^{- 1}$ and for the adsorption of hydrogen on nickel, the activation energy is $41.4 kJ mol^{- 1}$ . The logarithm of the ratio of the rates of chemisorption on equ …
JEE Main 2023View solution →
The number of colloidal systems from the following, which will have 'liquid' as the dispersion medium, is ____

Gem stones, paints, smoke, cheese, milk, hair cream, insecticide sprays, froth, soap lather.
JEE Main 2023View solution →
Coagulating value of electrolytes $AlCl_{3}$ and NaCl for $As_{2} S_{3}$ are 0.09 and 50.04 respectively. The coagulating power of $AlCl_{3}$ is $x$ times the coagulating power of NaCl . The value of $x$ is
____ :
JEE Main 2023View solution →
Ferric chloride is applied to stop bleeding because:
JEE Main 2023View solution →