The chemical shift of the CH3 protons in acetaldehyde is delta = 2.20 and that of the CHO proton is 9.80. What is the difference in local magnetic field between the two regions of the molecule when applied field is 15 T.

The chemical shift of the CH3 protons in acetaldehyde (ethanal) is δ = 2.20 and that of the CHO proton is 9.80. What is the difference in local magnetic field between the two regions of the molecule when the applied field is (a) 1.2 T, (b) 5.0 T?

The 13C NMR spectrum of ethanoic acid (acetic acid) shows a quartet centred at δ = 21 with a splitting of 130 Hz. When the same spectrum is recorded using proton decoupling, the multiplet collapses to a single line. Another quartet, but with a much smaller spacing, is also seen centred at δ =178; this quartet collapses when decoupling is used. Explain these observations.

A 400 MHz 'H NMR spectrum of a mixture of common organic solvents consisting of benzene (C,H6) 8 7.37; diethyl ether (C4H,1,0) § 3.49 and 8 1.22; and dichloromethane (CH;Clz) 8 5.30 is given below. Estimate the relative proportions (mole %) of the 3 components from the integrals in the spectrum. CH3-CH2-0- CH2-CH3 CI-CH2-CI benzene diethyl ether dichloromethane 'H NMR Spectrum (400 MHz, CDCI, solution) 3.5 3.4 ppm 1.3 1.2 ppm 7 5 3 2 1 ppm Compound Mole % benzene diethyl ether dichoromethane

Propanone (acetone, (CH3)2CO) has a strong absorption at 189 nm and a weaker absorption at 280 nm. Identify the chromophore and assign the absorptions to π* ← n or π* ← π transitions.

For 'H³°CI molecule, (N1/No) ratio at 300 K is 6.091 x 10² . Calculate the wavenumber ( in cm') for J=2→J=3 transition in the microwave spectrum of the molecule.

Calculate the wavenumber of the rotational transition from J=1 to J=2 of the HCl bond. The reduced mass of the molecule is 1.61x10-27 kg and its bond length is 1.275 Angstroms.

What is the difference in population of 13C spins between the upper and lower states in a magnetic field at 2T and 300K?