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

How the following conversions can be car | Class 12 Chemistry Chapter Haloalkanes and Haloarenes, Haloalkanes and Haloarenes 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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Study Tips for Answering NCERT Questions:

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Comments

Kavya
2023-10-11 14:09:05

Thanks to helping me

Deeksha
2020-11-28 06:10:44

Thanks allot

bhoomika
2020-09-17 23:20:46

thank you ....it helped me a lot

Sampada
2020-07-25 19:39:03

Thanku

Harsh
2019-11-29 21:04:01

Thank you so much

Mahesh chandra sarswat
2019-02-11 07:14:19

How will you carry out following conversionsof ethyne 1-butyne

Sombir
2018-06-29 22:34:34

In the 2 question ,in product there is a extra hydrogen attached to te c-atom

Sari mathi
2018-05-28 21:36:53

Super it easy to understand thanks

Kabir
2017-12-10 19:07:14

in (xix) its not tert butyl bromide real str. Dont be confuse guys i think they also have copied this ans from my cbse guide app there also it is wrong

Satvir singh
2017-05-18 21:13:18

apology for that yes there is one extra bromine in the structure ,it will be rePlaced by one methyl group but the structure arrangement will in the same format as shown in the answer

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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 19: How the following conversions can be carried out? (i) Propene to propan-1-ol (ii) Ethanol to b....

How the following conversions can be car | Class 12 Chemistry Chapter Haloalkanes and Haloarenes, Haloalkanes and Haloarenes NCERT Solutions

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