Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE Main 20199 AprilEvening Shift
Exam
JEE Main
Year
2019
Date
9 April
Shift
Evening Shift
Subject
Chemistry
Chapter
Surface Chemistry

JEE Main 2019 · 9 April · Evening Shift · Chemistry · Surface Chemistry

10mL of 1mM surfactant solution forms a monolayer covering 0.24c m...

10mL10mL of 1mM1mM surfactant solution forms a monolayer covering 0.24cm20.24c{m}^{2} on a polar substrate. If the polar head is approximated as a cube, what is its edge length?

Options

  1. A1.0pm1.0pm
  2. B0.1nm0.1nm
  3. C2.0pm2.0pm
  4. D2.0nm2.0nm

Correct answer

C. 2.0pm2.0pm

Step-by-step solution

Millimoles of surfactants =10×10−3=10−2= 10 \times {10}^{- 3} = {10}^{- 2}
Moles of surfactants =10−5= {10}^{- 5}
Number of molecules =6×1023×10−5=6×10+18= 6 \times {10}^{23} \times {10}^{- 5} = 6 \times {10}^{+ 18}
Surface area occupied by one molecule =0.246×1018=0.04×10−18cm2= \dfrac{0.24}{6 \times {10}^{18}} = 0.04 \times {10}^{- 18}c{m}^{2}
4×10−20=a24 \times {10}^{- 20} = {a}^{2}
a=2×10−10cm=2pma = 2 \times {10}^{- 10}cm = 2pm
Practice Surface Chemistry on Quantrex Academy →

More from Surface Chemistry

At a given temperature, 0.45 g of acetic acid in 50 mL of water is shaken with 1.0 g of… JEE Advanced 2026Adsorption of phenol from its aqueous solution on to fly ash obeys Freundlich isotherm.… JEE Advanced 2025Consider the following statements related to colloids. (I) Lyophobic colloids are not… JEE Advanced 202320mL of 0 . 5MNaCl is required to coagulate 200mL of As _ 2 S _ 3 solution in 2 hours.… JEE Main 2023Given below are two statements, one is labelled as Assertion A and the other is labelled… JEE Main 2023What happens when a lyophilic sol is added to a lyophobic sol? JEE Main 2023Four gases, A, B, C and D have critical temperatures 5 . 3, 33 . 2, 126 . 0 and 154 . 3K… JEE Main 2023The number of correct statements about modern adsorption theory of heterogeneous… JEE Main 2023 Full Surface Chemistry list All JEE Main PYQs