Problem 78
In the following reaction sequence, it is \(\mathrm{Q}\) which can decolourise colour of \(\mathrm{Br}_{2} / \mathrm{H}_{2} \mathrm{O}\) solution. $$ \text { D-Glucose } \stackrel{\stackrel{\circ}{\circlearrowright}}{\rightleftharpoons} \mathrm{P}+\mathrm{Q} $$ then ' \(\mathrm{P}\) ' is (A) Non-reducing sugar (B) Aldohexose (C) D-fructose (D) D-Mannose
Problem 79
Glucose on reaction with excess acetic anhydride form penta acetate, this reaction confirms about (A) - CHO group in glucose (B) Straight chain in glucose (C) Cyclic form of glucose (D) Number of \(-\mathrm{OH}\) group in glucose
Problem 80
The incorrect statement for vitamin-C (Ascorbic acid) is (A) Reacts with \(\mathrm{NaHCO}_{3}\) (B) It is L-Ascorbic acid (C) C-3 OH group is most acidic (D) It contains only one chiral centre
Problem 81
Which of the following terms are correct about enzyme? (A) Proteins (B) Dinucleotides (C) Nucleic acids (D) Biocatalysts
Problem 82
Which of the following monomers formbiodegradable polymers? (A) Caprolactum (B) Glycine + amino caproic acid (C) Ethylene glycol + phthalic acid (D) 3 -hydroxybutanoic acid \(+3\)-hydroxypentanoic acid
Problem 84
In the following reaction sequence, "S" is (A) D-Glucose (B) D-Mannose (C) D-Fructose (D) None of these
Problem 86
Which of the following is an example of synthetic rubber? (A) Polychloroprene (B) Polyacrylonitrile (C) Buna-N (D) cis-polyisoprene
Problem 87
Aldohexoses P and Q formed from Aldopentose R via Kilani-Fischer synthesis. Nitric acid oxidizes \(\mathrm{P}\) to an optically active aldaric acid and \(\mathrm{Q}\) to an optically inactive aldaric acid and \(\mathrm{R}\) to an optically active aldaric acid. Wohl degradation of \(\mathrm{R}\) forms \(\mathrm{S}\), which is oxidized by nitric acid to an optically active aldaric acid. Wohl degradation of S forms (+)-glyceraldehyde. Identify \(\mathrm{P}\).
Problem 90
Which of the following polymers can have strong intermolecular forces? (A) Nylon (B) Polystyrene (C) Rubber (D) Polyesters
Problem 91
Indophenol \(\mathrm{O}=\mathrm{N}-\bigcirc>\mathrm{OH}\) is an acid-base indicator obtained during Libermann nitroso test of phenol. It gives green colour in the presence of (A) \(\mathrm{NaOH}\) (B) \(\mathrm{H}_{2} \mathrm{SO}_{4}\) (C) \(\mathrm{H}_{2} \mathrm{O}\) (D) None of these
