Photo AI
This question is about compound X with the empirical formula C2H6O - AQA - A-Level Chemistry - Question 6 - 2022 - Paper 2
Question 6
This question is about compound X with the empirical formula C2H6O. Figure 2 shows the infrared spectrum of X. Figure 3 shows the 1H NMR spectrum of X. Table 3 gi... show full transcript
Worked Solution & Example Answer:This question is about compound X with the empirical formula C2H6O - AQA - A-Level Chemistry - Question 6 - 2022 - Paper 2
Step 1
Figure 2: Infrared Spectrum Analysis
Answer
In the infrared spectrum (Figure 2), we observe a broad absorption band around 3200-3400 cm⁻¹, which indicates the presence of an -OH group typical of alcohols. Additionally, there are peaks around 1700-1750 cm⁻¹ that suggest C=O functionality, which is consistent with possible ketones or aldehydes.
Step 2
Figure 3: 1H NMR Spectrum Analysis
Answer
The 1H NMR spectrum (Figure 3) displays four distinct peaks. The integration values indicated in Table 3 show:
- Peak at 3.9 ppm suggests the presence of a hydrogen on a carbon adjacent to an electronegative atom (like oxygen from -OH), typical of alcohols.
- Peak at 3.7 ppm, being a singlet, corresponds to a methyl group (-CH3) adjacent to a methylene group (-CH2-).
- The integration values suggest one proton for peak 2 (singlet) likely indicates an -OH hydrogen.
- Peak at 2.1 ppm indicates a methylene group likely next to an -OH group.
Step 3
Table 3: Chemical Shifts and Splitting Patterns
Answer
From Table 3:
- Chemical shifts support our findings in the IR and NMR spectrums. The splitting patterns (quartet and singlet) confirm that we have a structure containing different environments for hydrogen atoms, suggesting a typical structure like ethanol.
- The integration values (3 for the peak at 3.7 ppm and 1 for the peak at 3.9 ppm) align with our interpretations indicating the likely structure of compound X as ethanol (C2H5OH), corroborating HNMR and IR data.