A solution of glucose in water is labell | Class 12 Chemistry Chapter Solutions, Solutions NCERT Solutions

Welcome to the NCERT Solutions for Class 12 Chemistry - Chapter Solutions. This page offers a step-by-step solution to the specific question from Exercise 2, Question 5: . With detailed answers and explanations for each chapter, students can strengthen their understanding and prepare confidently for exams. Ideal for CBSE and other board students, this resource will simplify your study experience.

Question 5:

A solution of glucose in water is labelled as 10% w/w, what would be the molality and mole fraction of each component in the solution? If the density of solution is 1.2 g mL-1, then what shall be the molarity of the solution?

Answer:

10% w/w solution of glucose in water means that 10 g of glucose in present in 100 g of the solution i.e., 10 g of glucose is present in (100 - 10) g = 90 g of water.

Molar mass of glucose (C6H12O6) = 6 × 12 + 12 × 1 + 6 × 16 = 180 g mol - 1

Then, number of moles of glucose = 10 / 180 mol

= 0.056 mol

∴ Molality of solution = 0.056 mol / 0.09kg  = 0.62 m

Number of moles of water = 90g / 18g mol-1 = 5 mol

Mole fraction of glucose  (xg) = 0.056 / ( 0.056+5) = 0.011

And, mole fraction of water xw = 1 - xg

= 1 - 0.011 = 0.989

If the density of the solution is 1.2 g mL - 1, then the volume of the 100 g solution can be given as:

= 100g / 1.2g mL-1

= 83.33 mL

=83.33 x 10-3 L

∴ Molarity of the solution = 0.056 mol / 83.33 x 10-3 L

= 0.67 M


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Comments

  • Devanshi patkr
  • Jul 31, 2020

Thx for helping me 😊


  • Sonali
  • Jul 07, 2019

1000/90 can be written as 0.09


  • Sonali
  • Jul 07, 2019

1000/90 can be written as 0.09


  • Nazish
  • Jun 08, 2019

Why 19 was divided by 18.instead of 180


  • Amarjeet
  • May 24, 2019

From where 0.9 is there


  • Viku
  • May 20, 2019

0.9 kha s aaya h


  • Monika
  • Mar 30, 2019

When we get 0.01


  • Abab
  • Mar 17, 2019

Hey


  • Aksh
  • Jan 06, 2019

What if density is not given


  • Surendra singh kohli
  • Apr 25, 2018

Very interesting question


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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 5: A solution of glucose in water is labelled as 10% w/w, what would be the molality and mole fraction ....