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

Density of a gas is found to be 5.46 g/d | Class 11 Chemistry Chapter States of Matter, States of Matter 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

Ash
2019-11-10 11:55:59

Thanks

Vivek
2019-09-29 05:57:37

Thanx

B ghosh
2019-09-21 18:15:27

How can we compare the equations

Harshit Rathi
2019-04-05 09:24:17

What is the use of 5.46 in this numerical

PB
2019-02-19 13:22:03

Thanku ji

Sukhpal gill
2018-10-27 07:04:05

Good

M Datta
2017-12-17 09:56:59

Thanks

M Datta
2017-12-17 09:56:31

In the last step that would be: (300Ã5.46)/(2Ã273) ð

Mehakpreet kaur
2017-09-24 20:23:08

Thanks

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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 9: Density of a gas is found to be 5.46 g/dm3 at 27 °C at 2 bar pressure. What will be its density ....

Density of a gas is found to be 5.46 g/d | Class 11 Chemistry Chapter States of Matter, States of Matter NCERT Solutions

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