(a)[1]
State the roles of TMS and $\text{D}_2\text{O}$ in NMR spectroscopy.
(b(i))[2]
Complete Table 7.1 to show the number of peaks seen in the proton ($^1\text{H}$) NMR spectrum and in the carbon-13 NMR spectrum for each named compound.
(b(ii))[2]
State all the ketones with molecular formula $\text{C}_5\text{H}_{10}\text{O}$ that show: • a doublet in the proton ($^1\text{H}$) NMR spectrum. • a singlet in the proton ($^1\text{H}$) NMR spectrum.
(c(i))[1]
Determine the number of chiral carbon atoms in one molecule of cortisone.
(c(ii))[1]
Cortisone is reacted with excess $\text{NaBH}_4$. State the molecular formula of the organic product formed.
(c(iii))[1]
Cortisone is an optically active molecule. Explain the meaning of optically active.