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

What is the number of photons of light w | 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

Makwana darsh
2019-09-04 10:45:15

The right answer is 2.012Ã10^16

Snigdha
2019-08-22 20:54:47

Yaah this is not the correct answer

Sachin
2019-08-09 19:56:44

This is not correct answer

RS
2019-08-09 05:54:14

Correct answer will be 2.012ÃÃ10^16 photons

Ujjwal kashyap
2019-08-06 20:24:39

Sir, the answer will be 2.014*10^16

dad
2019-07-03 14:12:20

this is shit

Manju Shrestha
2019-06-26 22:11:39

I have not understood nicely.....

Manju Shrestha
2019-06-26 21:30:42

Thank u.... for this solution...

Ishaan Chopra
2019-06-16 15:55:15

Energy of photon will be 4.965 * 10^-17 and hence the answer will be 2.014 * 10^16 photons

Raghunandan m s
2019-06-16 07:40:20

Write but some corrections needed

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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 8: What is the number of photons of light with a wavelength of 4000 pm that provide 1 J of energy?....

What is the number of photons of light w | Class 11 Chemistry Chapter Structure of Atom, Structure of Atom NCERT Solutions

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