Spectrum of Acetaldehyde CH3CHO Recorded at 200 MHz & 400 MHz Questions

I’m working on a chemistry multi-part question and need guidance to help me study.

The spectrum of acetaldehyde, CH3CHO, shown below, is recorded at 200 MHz and 400 MHz.

1. Which of the peaks belongs to the proton in the -CHO group? [ Select ] [“9.8 ppm“, “2.2 ppm“]

2. Is the following statement True or False: “The spin-spin coupling constant J depends on the strength of the magnetic field B0.” [ Select ] [“False“, “True“]

3. What is the strength of the magnetic field B0 for the spectrum recorded at 200 MHz? [ Select ] [“9.40 T“, “4.7 T“, “1.14 T“]