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

How much energy is required to ionise a | Class 11 Chemistry Chapter Structure of Atom, Structure of Atom 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

Shubham shriwas
2019-08-20 22:13:14

Mast wala answer dene ke liye thanks sir

Sujal Rajput
2019-08-12 15:58:19

What the hell

Kritika
2019-08-12 11:19:31

Thanks

Krishnendu
2019-08-01 21:28:05

Such a worst answer I have ever seen

Krishnendu
2019-08-01 21:04:40

How at first n2=infinity

Iswarya
2019-07-07 21:27:47

Grammatical mistake

Iswarya
2019-07-07 21:15:25

Thanks ,any how good

Iswarya
2019-07-07 21:14:16

Typing must be clear

Liana
2019-07-07 19:02:25

I think some steps are missing

Peeku
2019-07-04 21:03:45

Thank u sir

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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 14: How much energy is required to ionise a H atom if the electron occupies n = 5 orbit? Compare your an....

How much energy is required to ionise a | Class 11 Chemistry Chapter Structure of Atom, Structure of Atom NCERT Solutions

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