Calculate the molarity of a solution of | Class 11 Chemistry Chapter Some Basic Concepts of Chemistry, Some Basic Concepts of Chemistry NCERT Solutions

Question:

Calculate the molarity of a solution of ethanol in water in which the mole fraction of ethanol is 0.040 (assume the density of water to be one).

Answer:

Mole fraction of C2H5OH=   .................1

Let the moles of C2H5OH= X

Now density of water = 1 (given)

And the weight of 1000ml of water = volume * density (from density = mass/volume)

= 1000 x 1=1000g

Therefore moles of water = 1000/18= 55.55 mol (18g is molecular mass of water)

Also mole fraction of C2H5OH= 0.040 (given)

Putting the values in equation 1,we get

=0.040=X/X+55.55

=0.040X+2.222 = X

OR X= 2.3145 mol

Molarity of solution = 2.314 M

 

 


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 Some Basic Concepts of Chemistry.
  • 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

  • Sameer
  • 2019-07-02 20:02:19

Calculate the the molarity solution of methanol in 1 litre offer water in which of the mole fraction of is 0.5


  • Mukesh jain
  • 2019-06-26 11:02:30

In this question water density given but still need to solve this question not have density of solution so a/c to my opinion that question fandamentically wrong. And if think water density is equal to solution density than answers will be2.01M


  • ISMAIL
  • 2019-06-09 16:11:36

2.22/1.040=2.14461~2.1 Therefore,Molarity of Ethanol= 2.1M


  • ISMAIL
  • 2019-06-09 16:09:14

WTF! 2.22÷1.040 = 2.134615~2.1M


  • sachin
  • 2019-05-02 13:51:22

write answer is 2.22


  • Shanaya
  • 2019-04-27 14:35:32

Volume of water i.e 1 litre is converted to 1000ml


  • Shanaya
  • 2019-04-27 14:28:13

Volume of water i.e 1 litre is converted to 1000ml


  • Wajahat
  • 2018-12-11 14:51:25

Why vol of water 1000 why God why


  • phd in chemistry
  • 2018-11-12 21:56:10

the answer is totally wrong,it should be 2.09 M


  • Abhi
  • 2018-09-15 08:44:05

Thanks


Comment(s) on this Question

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 29: Calculate the molarity of a solution of ethanol in water in which the mole fraction of ethanol is 0.....