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

If the speed of light is 3.0 × 108 | Class 11 Chemistry Chapter Some Basic Concepts of Chemistry, Some Basic Concepts of 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

Shreya
2020-05-10 21:49:57

Thanks for the solution but what is na here.

Ujjwal Chaurasia
2019-11-16 20:12:46

Thanks for confirmation

Shahtab
2019-10-03 20:01:43

What is ns here?

Umar
2019-08-08 12:25:13

Thanks alot

Aman Gupta
2019-08-05 18:53:08

Thanks

Teena
2019-05-05 18:25:27

Wow

Prakhar Crazy
2018-08-04 22:02:19

Thanks

Sahil
2018-06-14 20:24:49

Thnks for sugesation

Navneet singh
2018-05-08 21:53:13

thanks alot

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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 22: If the speed of light is 3.0 × 108 ms–1, calculate the distance covered by light in 2.00....

If the speed of light is 3.0 × 108 | Class 11 Chemistry Chapter Some Basic Concepts of Chemistry, Some Basic Concepts of Chemistry NCERT Solutions

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