Give the name of a suitable substance for each phase, or describe each one precisely.
Explain what is meant by retention time.
Calculate the percentage of B in the mixture. Show your calculations.
Complete Table 9.1 so that it shows the number of peaks in the carbon-13 NMR spectrum for each of the five isomers of $\text{C}_5\text{H}_{10}\text{O}_2$ that contain an ester group.
State how many peaks would appear in the proton ($^1\text{H}$) NMR spectrum of methyl butanoate, $\text{CH}_3\text{CH}_2\text{CH}_2\text{CO}_2\text{CH}_3$. Name every splitting pattern present in this spectrum.
Deduce the structures of the two esters D and E, then draw their displayed formulae in the boxes below. Both have the molecular formula $\text{C}_5\text{H}_{10}\text{O}_2$.
The spectrum of D has a quartet at $\delta = 4.1$. On your structure in (i), identify the protons that produce this quartet by labelling them with the letter F. Explain why this peak is split into a quartet.
The spectrum of E shows a doublet at $\delta = 1.1$. On your structure in (i), identify the protons responsible for this doublet by labelling them with the letter G. Explain why this peak has a chemical shift of $1.1$.
Deduce the structures of the two esters $D$ and $E$ and draw their displayed formulae in the boxes below. $D$: $\text{C}_5\text{H}_{10}\text{O}_2$. $E$: $\text{C}_5\text{H}_{10}\text{O}_2$.
The spectrum of $D$ contains a quartet at $\delta\ 4.1$. Identify the protons responsible for this quartet on your structure in (i) by labelling them with the letter $F$. Explain why this peak is split into a quartet.
The spectrum of $E$ shows a doublet at $\delta\ 1.1$. Identify the protons responsible for this doublet on your structure in (i) by labelling them with the letter $G$. Explain why this peak has a chemical shift of $1.1$.