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GATE 2023 CY โ€“ Question 12

Organic Chemistry ยท Experimental Techniques in Organic Chemistry: Optical rotation (polarimetry). Application of various chromatographic techniques such as thin-layer, column, HPLC and GC. Applications of UV-visible, IR, NMR spectroscopy and Mass spectrometry in the structural determination of organic molecules. ยท 1 mark ยท Multiple choice

The compound which gives a fragment at ๐‘š/๐‘ง = 124[M+H]+ is

Diagram for GATE 2023 CY question 12
  1. Structure A
  2. Structure B
  3. Structure C
  4. Structure D

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Show answer and explanation

Correct answer: (B) Structure B

Explanation

StructureB is theophylline, C7H8N4O2, with nominal neutral mass180. Loss of methyl isocyanate, CH3NCO(57 Da), leaves a123 Da neutral fragment whoseprotonated ion is 124. The different hydrogenation/oxygenation in A, C, D changes thisfragment mass.

Thus **B**.