Chemistry 9701 · AS & A Level · States of matter

States of matter — practice question

Figure 7.1 shows the structure of compound $\textbf{P}$.
(a(i))[1]

$\textbf{P}$ is optically active. On the structure of $\textbf{P}$ in Fig. 7.1, use an asterisk $(*)$ to show every chiral carbon atom.

(a(ii))[2]

Plane polarised light is directed through a pure sample of one enantiomer of $\textbf{P}$. The test is then carried out again with a pure sample of the other enantiomer of $\textbf{P}$. Describe the outcomes of these two experiments, making clear both the similarities and the differences.

(b(i))[1]

$\textbf{P}$ can be used to make compound $\textbf{Q}$ in one step. Give the structural formula of the substance added to $\textbf{P}$ to form $\textbf{Q}$, and give the formula of the other product formed in this reaction.

(b)

$P$ can be converted into compound $Q$ in one step.

(b(ii))[3]

When an ester reacts with $LiAlH_4$ in dry ether, the ester linkage is split by the addition of four hydrogen atoms and two alcohols form. Draw the structures of the products obtained when $Q$ is treated with excess $LiAlH_4$ in dry ether.

(b(iii))[3]

Compare the relative basicities of compound $P$, compound $Q$ and phenylamine. least basic $<$ __________ $<$ __________ $<$ most basic. Explain your reasoning.

(c)

Compound $R$ can be made from $P$ in a two-step reaction shown in Fig. 7.2.

(c(i))[2]

Identify the reagents and conditions for the two reaction steps. step 1 ........................................................ step 2 ........................................................

(c(ii))[2]

Complete Table 7.1 by drawing the structures of the organic products formed when $R$ is treated separately with the given reagents: $\mathrm{HNO_2(aq)}$ at $4^{\circ}\text{C}$; an excess of $\mathrm{Br_2(aq)}$ at room temperature.

(d)

$P$ can be used to form compound $T$.

(d(i))[1]

In aqueous solution, $T$ has a property known as an isoelectric point. Explain what is meant by the term isoelectric point.

(d(ii))[2]

$T$ can polymerise under suitable conditions. No other monomer takes part in this reaction. Draw a section of the polymer chain formed that contains three $T$ monomers. Identify the repeat unit on your diagram.

Worked solution & mark scheme

This 17-mark question has a full step-by-step worked solution and mark scheme. One marking point: Chiral molecule drawn correctly

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