Chemistry 9701 · AS & A Level · Analytical techniques

Analytical techniques — practice question

W is a colourless liquid, and its structure is shown in Fig. 5.1.
(a(i))[1]

Deduce the empirical formula for W.

(a(ii))[4]

As shown in Table 5.1, two different reagents are each added to separate samples of W. Complete Table 5.1.

(b(i))[2]

Deduce the number of sigma ($\sigma$) bonds and pi ($\pi$) bonds in Z.

(b(ii))[1]

W reacts with $\text{LiAlH}_4$ to produce Y. Draw the structure of Y.

(b(iii))[1]

Identify the role of $\text{LiAlH}_4$ when it reacts with W.

(b(iv))[1]

Suggest the reagent and conditions required when W is converted into Z.

(b(v))[2]

Identify the bond and functional group responsible for each of the absorptions labelled A, B, C and D in Fig. 5.4.

(v)[2]

Identify the bond and functional group responsible for each absorption labelled A, B, C and D in Fig. 5.4.

(vi)[1]

Z is used to produce addition polymer Q. Draw the repeat unit of polymer Q.

(c)[1]

Poly(ethene) is an addition polymer made from ethene. Explain why ethene reacts with electrophiles but poly(ethene) does not.

Worked solution & mark scheme

This 16-mark question has a full step-by-step worked solution and mark scheme. One marking point: Molecular formula is $\mathrm{C_2H_3O}$

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