Enumerate the reactions of D-glucose whi | Class 12 Chemistry Chapter Biomolecules, Biomolecules NCERT Solutions

Welcome to the NCERT Solutions for Class 12 Chemistry - Chapter Biomolecules. This page offers a step-by-step solution to the specific question from Exercise 2, Question 10: . 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 10:

Enumerate the reactions of D-glucose which cannot be explained by its open chain structure.

Answer:

 

(1) Aldehydes give 2, 4-DNP test, Schiff's test, and react with NaHSO4 to form the hydrogen sulphite addition product. However, glucose does not undergo these reactions.

(2) The pentaacetate of glucose does not react with hydroxylamine. This indicates that a free -CHO group is absent from glucose.

(3) Glucose exists in two crystalline forms - ∝ and β. The ∝-form (m.p. = 419 K) crystallises from a concentrated solution of glucose at 303 K and the β-form (m.p = 423 K) crystallises from a hot and saturated aqueous solution at 371 K. This behaviour cannot be explained by the open chain structure of glucose.

 


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  • Read the question carefully and focus on the core concept being asked.
  • Reference examples and data from the chapter when answering questions about Biomolecules.
  • 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.
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Comments

  • Ayush
  • Jul 19, 2019

What how to learn such a big answer.


  • Ayush
  • Jul 19, 2019

What


  • Komal
  • Mar 10, 2019

Thank you


  • Ankit ara
  • Dec 26, 2016

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  • manasa
  • Jun 20, 2016

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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 10: Enumerate the reactions of D-glucose which cannot be explained by its open chain structure.....