The diagram shows the mass spectrum of an organic compound - HSC - SSCE Chemistry - Question 4 - 2019 - Paper 1
Question 4
The diagram shows the mass spectrum of an organic compound.
Which compound was analysed?
A. Butan-1-amine
B. Butanoic acid
C. Ethanoic acid
D. Iron(II) sulfide
Worked Solution & Example Answer:The diagram shows the mass spectrum of an organic compound - HSC - SSCE Chemistry - Question 4 - 2019 - Paper 1
Step 1
Identify significant m/z values from the spectrum
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Answer
The mass spectrum shows prominent peaks at m/z values of 60, 73, and 88. The m/z value at 60 is especially significant as it often indicates a molecular ion, which can help identify the compound.
Step 2
Determine the possible molecular formula
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Answer
For the peak at m/z 60, we can consider common organic compounds that have a molecular weight around this value. The relevant compounds would typically include derivatives of carboxylic acids and amines.
Step 3
Analyze each option based on molecular weight
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Answer
Butan-1-amine (C4H11N) - Total mass: 73 g/mol
Butanoic acid (C4H8O2) - Total mass: 88 g/mol
Ethanoic acid (C2H4O2) - Total mass: 60 g/mol
Iron(II) sulfide (FeS) - Total mass: 87 g/mol
Given that the molecular ion is likely at m/z 60, Ethanoic acid is the correct identification.
Step 4
Final conclusion
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Answer
Based on the analysis of the peaks and corresponding molecular weights, the organic compound analyzed is B. Butanoic acid.