Question

I thought Upfield meant further away from molecules such as O?

Your answer is incorrect. Try again The 1H NMR signal for which of the indicated protons will occur at the lowest frequency (most upfield signal)? IV IV

Answer 1

NOTE: UPFIELD means in comparison low chemical shift value.

The NMR chemical shift scale usually shows from delta -1 to 14.0 ppm. In the ppm scale, upfield signal means lower chemical shift value. [(i.e) low delta - value] - lower field signal means higher chemical shift value. (or) downfield [(i.e) high delta - value] rightdoublearrow Diagram: - The given structure: - rightarrow Among the labeled protons, proton - I will appear on most upfield side in the ppm scale. therefore Approximate delta value are (I) rightarrow approximately 2.30 ppm (II), (III), (IV) rightarrow 7 - 8.00 ppm (V) rightarrow approximately 12.00 ppm therefore So, correct answer is - (I) NOTE: UPFIELD means in comparison low chemical shift value.