Action of soap is due to emulsification | Class 12 Chemistry Chapter Surface Chemistry, Surface Chemistry NCERT Solutions

Question:

Calculate the molecular mass of the following:
(i) H2O
(ii) CO2
(iii) CH4

Answer:

Molecules are made up of atoms & are  quite small, therefore the actual mass of a molecule cannot be detrmined.It is expressed as the relative mass.C-12 isotope is used to express the relative molecular masses of substances.Thus  molecular mass of a substance may be defined as: the average relative mass of its molecule as compared to the mass of carbon atom taken as 12 amu.

(i) H2O:

The molecular mass of water, H2O

= (2 × Atomic mass of hydrogen) + (1 × Atomic mass of oxygen)

= [2(1.0084) + 1(16.00 u)]

= 2.016 u + 16.00 u

= 18.016

= 18.02 u

(ii) CO2:

The molecular mass of carbon dioxide, CO2

= (1 × Atomic mass of carbon) + (2 × Atomic mass of oxygen)

= [1(12.011 u) + 2 (16.00 u)]

= 12.011 u + 32.00 u

= 44.01 u

(iii) CH4:

The molecular mass of methane, CH4

= (1 × Atomic mass of carbon) + (4 × Atomic mass of hydrogen)

= [1(12.011 u) + 4 (1.008 u)]

= 12.011 u + 4.032 u

= 16.043 u


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Comments

  • Ravleen kaur
  • 2020-06-10 10:14:49

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  • Yatharth
  • 2019-12-12 21:21:44

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  • Swati
  • 2019-07-23 23:36:18

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  • Damini kashyap
  • 2019-04-29 17:44:13

Thank u so much for this answer...


  • SANDEEP SUMAN
  • 2018-12-29 14:36:55

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  • 2018-09-18 15:13:18

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  • 2018-09-18 15:12:43

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  • Mira moinuddin
  • 2018-08-16 20:22:14

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  • Aditigoyal
  • 2018-07-04 21:27:26

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  • AKHILA R KRISHNAN
  • 2017-09-02 08:02:08

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Comment(s) on this Question

Welcome to the NCERT Solutions for Class 12 Chemistry - Chapter . This page offers a step-by-step solution to the specific question from Excercise 2 , Question 18: Action of soap is due to emulsification and micelle formation. Comment.....