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An unknown organic compound has a molecular formula of C4H8O - VCE - SSCE Chemistry - Question 8 - 2020 - Paper 1
Question 8
An unknown organic compound has a molecular formula of C4H8O. The compound is non-cyclic and contains a double bond. The infra-red (IR) spectrum of the molecule is s... show full transcript
Worked Solution & Example Answer:An unknown organic compound has a molecular formula of C4H8O - VCE - SSCE Chemistry - Question 8 - 2020 - Paper 1
Step 1
What does the region 3100–4000 cm⁻¹ indicate about the bonds in C4H8O?
Answer
The region from 3100 to 4000 cm⁻¹ in the IR spectrum is indicative of the presence of C-H bonds in alkenes and alkynes. In this case, since there is no O-H peak present (which would typically appear in the range of 3200-3600 cm⁻¹ for alcohols), we can conclude that the compound does not contain an -OH group, confirming it is not an alcohol. The presence in this region suggests that the compound likely contains a C=C double bond, which is consistent with its structure.