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

What role does the molecular interaction | Class 12 Chemistry Chapter Solutions, Solutions 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

Rohit Chalotra
2019-08-04 10:33:25

Thanks sergeant

hema
2019-07-23 03:19:55

Thank you very much sir

Kriti
2019-04-16 13:47:07

Thanks for your help

Kriti
2019-04-16 13:46:44

Thanks for your help

Assss
2019-03-28 18:48:32

Your answer is wrong. As molecular mass increase solubility of a gas increases.

varshan
2019-03-18 20:01:38

Thanks

SG
2019-02-06 19:24:27

see ncert pg no. 45 last para for increased or decreased vapour pressure confusion.

Prince Sekhon
2018-06-21 17:58:01

Perfect ans

Raveena gupta
2018-05-08 02:12:14

Thanks

Some dude
2018-04-05 01:15:59

Fukin wrong pleb Interactions get stronger leading to stronger bonds and less vapour and hence less vapour pressure causing the negative deviation from Raoults law

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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 10: What role does the molecular interaction play in a solution of alcohol and water?....

What role does the molecular interaction | Class 12 Chemistry Chapter Solutions, Solutions NCERT Solutions

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