Preparation of ethers by acid dehydratio | Class 12 Chemistry Chapter Alcohols Phenols and Ethers, Alcohols Phenols and Ethers 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


Study Tips for Answering NCERT Questions:

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  • Read the question carefully and focus on the core concept being asked.
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Comments

  • Vedant
  • 2019-10-24 10:41:24

Uumda khele aap


  • Pranjal
  • 2019-10-08 14:26:11

Nice effort good try


  • Pranjal
  • 2019-10-08 14:25:32

Nice effort


  • Shalini gupta
  • 2019-08-01 21:03:58

Mujhe ether ke kuch example solve krbe ke liye chaiye


  • Pragati Mohire
  • 2019-04-10 22:01:34

Good job


  • Nupur
  • 2019-03-11 19:06:43

Accurate answer.


  • Eknoor singh
  • 2019-02-04 19:32:01

Best answers


  • Anushka Singh
  • 2018-12-08 12:08:54

Good job


  • Aniket singh
  • 2018-10-28 22:14:45

Suitable answer


  • Shanti pandey
  • 2018-07-29 08:55:50

Always sweet and short and best answer


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 27: Preparation of ethers by acid dehydration of secondary or tertiary alcohols is not a suitable method....