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

What are the necessary conditions for an | Class 11 Chemistry Chapter Hydrocarbons, Hydrocarbons 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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Reference examples and data from the chapter when answering questions about Hydrocarbons.
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Comments

PRAYAS
2019-03-31 14:16:51

Mast

Dhruv
2019-03-31 13:00:27

thanx

paddy
2019-03-10 19:26:03

thnx

Irtiqa
2019-02-21 14:29:16

Good explaining ð¤ð

chaitrali
2019-02-18 18:20:29

thnx

chaitrali
2019-02-18 18:20:02

perfect ....thx

Karan
2019-01-20 16:16:52

Nice

Preeti
2019-01-16 19:20:59

Nice

Monishka
2018-10-31 21:11:10

Gud thanks for this

Frank
2018-03-28 06:31:59

Osm

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Welcome to the NCERT Solutions for Class 11 Chemistry - Chapter . This page offers a step-by-step solution to the specific question from Excercise 1 , Question 11: What are the necessary conditions for any system to be aromatic?....

What are the necessary conditions for an | Class 11 Chemistry Chapter Hydrocarbons, Hydrocarbons NCERT Solutions

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