19.5 g of CH2FCOOH is dissolved in 500 g | 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


Study Tips for Answering NCERT Questions:

NCERT questions are designed to test your understanding of the concepts and theories discussed in the chapter. Here are some tips to help you answer NCERT questions effectively:

  • Read the question carefully and focus on the core concept being asked.
  • Reference examples and data from the chapter when answering questions about Solutions.
  • Review previous year question papers to get an idea of how such questions may be framed in exams.
  • Practice answering questions within the time limit to improve your speed and accuracy.
  • Discuss your answers with your teachers or peers to get feedback and improve your understanding.

Comments

  • lafo
  • 2019-11-27 00:55:41

Why do we take, K(f) to be 1.86?


  • Subham
  • 2019-06-01 20:48:27

Value of c will be equals to molality


  • Prince bharti
  • 2019-05-28 14:22:10

Great job


  • Prince bharti
  • 2019-05-28 14:21:30

Great job


  • priya
  • 2019-05-24 00:16:29

What a explanation


  • Hets
  • 2019-05-10 00:22:28

How the value of C is calculated for Ka...???


  • Ishan
  • 2019-03-06 16:20:11

C can be calculated by c=n/v


  • Akash shaw
  • 2018-12-18 12:08:20

How the value of 'C' is calculated for Ka value.


  • kandiwali
  • 2017-06-27 18:22:45

Great hard work.


Comment(s) on this Question

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 33: 19.5 g of CH2FCOOH is dissolved in 500 g of water. The depression in the freezing point of water obs....