Final answer:
Ha signal at 7.98 ppm (also 7.93 ppm in another reference), Hb signal at 6.03 ppm (also 5.92 ppm in another reference), Hc signal at 8.00 ppm (6.20-6.45 ppm range in another reference), Hd signal at 5.88 ppm (6.20-6.64 ppm range in another reference).
Step-by-step explanation:
The student is asking to label the signals due to Ha, Hb, Hc, and Hd in the 1H NMR spectra. To label the signals, we need to analyze the information provided in the given references. From the Aromatic Proton Shifts section, we can identify the chemical shifts of the protons. Looking at the relevant data, we can assign the signals as follows:
- Ha: Shift at 7.98 ppm (7.93 ppm in another reference)
- Hb: Shift at 6.03 ppm (5.92 ppm in another reference)
- Hc: Shift at 8.00 ppm (6.20-6.45 ppm range in another reference)
- Hd: Shift at 5.88 ppm (6.20-6.64 ppm range in another reference)