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Classification of Elements and Periodicity in Properties
Calculate the molecular mass of the following: (i) H2O (ii) CO2 (ii...

Explain why cations are smaller and anio | Class 11 Chemistry Chapter Classification of Elements and Periodicity in Properties, Classification of Elements and Periodicity in Properties 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

Priyanka
2019-09-02 23:19:58

How can the cation & anion both have positively charged

RACHANA
2018-12-18 14:53:28

How can bth anion nd cation be positively charged

karan
2018-09-14 12:13:38

well explanation

Parmad
2018-06-01 21:52:32

You should be more informative

rishikanta
2016-12-01 08:58:52

Great ans

akarsh singh
2016-09-19 17:51:30

nice

SATVIR SINGH
2016-08-04 09:29:52

Anions are negatively charged while cations are positively charged.there is a typing mistake

Rishita
2016-08-02 05:30:33

How can bth anion nd cation be positively chargedð

saurabh singh
2016-03-18 11:56:32

nice

madhu
2015-11-27 19:16:39

yo grl!!

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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 13: Explain why cations are smaller and anions larger in radii than their parent atoms?....

Explain why cations are smaller and anio | Class 11 Chemistry Chapter Classification of Elements and Periodicity in Properties, Classification of Elements and Periodicity in Properties NCERT Solutions

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