本题目来源于试卷: Classification of Matter A.2 Classification of Organic Compounds，类别为 IB化学
[单选题]
Compound X has a molecular mass of 148.
The mass spectrum of compound X contains a peak at m/z = 117.
Which of the following spectral fragments is lost from compound X to produce this peak in the mass spectrum?
Atomic masses (amu) C=12C=12, H=1H=1, O=16O=16
A. $CH_2CH_3$
B. $COOH$
C. $CH_3O$
D. $CO$
参考答案: C
本题详细解析:
Explanation: The masses of options A, B, C and D are 29, 45, 31 and 28, respectively.
The mass of the fragment ion is 148 - 117 = 31, making option C correct.
This question is of moderate difficulty as two simple calculations are required.
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