Which of the given statement is not true for glucose? 4 4 (A) The pentacetate glucose does not react — Biomolecules Chemistry Question
Question
Which of the given statement is not true for glucose? 4 4 (A) The pentacetate glucose does not react with hydroxylamine to give oxime. (B) Glucose reacts with hydroxylamine to form oxime. (C) Glucose gives Schiff's test for aldehyde. (D) Glucose exists in two crystalline forms and .
💡 Solution & Explanation
Glucose exists in two crystalline forms and which are anomers of each other. Glucose does not react with Schiff’s reagent because after the internal cyclisation, it forms either -anomer or -anomer. In these forms, free aldehydic group is not present. Glucose forms open chain structure in aqueous solution which contains aldehyde at chain end. This aldehydic group reacts with NH OH to form oxime. On the other hand, glucose penta acetate being a cyclic structure even in aqueous form does not have terminal carbonyl group. Therefore, it will not react with NH OH.