18.
A compound shows a proton-NMR peak at 240 Hz downfield from TMS peak in a spectrometer operating at 60 MHz. Then the value of chemical shift (δ) and τ (in ppm) relative to TMS is
A:
6 ppm, 4 ppm
B:
4 ppm, 6 ppm
C:
2 ppm, 3 ppm
D:
3 ppm, 2 ppm
The answer is:
B