Chemistry 9701 · AS & A Level · Hydrocarbons

Hydrocarbons — practice question

4-nitromethylbenzene may be made by an electrophilic substitution reaction, as illustrated.
(a(i))[1]

This reaction also yields an isomer of 4-nitromethylbenzene as a side-product. Draw the structure of this side-product.

(a(ii))[1]

Write an equation for the reaction between $\text{HNO}_3$ and $\text{H}_2\text{SO}_4$ that produces the electrophile for this reaction.

(a(iii))[3]

Describe how the structure and bonding of the six-membered ring in intermediate T differs from that in methylbenzene.

(b(i))[1]

Give the systematic name of compound W.

(b(ii))[6]

Suggest the reagents and conditions for steps 1-5.

(c)[2]

Suggest how the basicity of benzocaine would compare to that of ethylamine. Explain your answer.

(d(i))[1]

Predict the number of peaks that would be observed in the carbon-13 NMR spectrum.

(d(ii))[1]

Suggest why $ CDCl$_3$ and not $ CHCl$_3$ is used as the solvent when obtaining a proton NMR spectrum.

(d(iii))[4]

Use the Data Booklet and the spectrum in (d)(ii) to complete the table for the proton NMR spectrum of benzocaine. The actual chemical shifts, $\delta$, for the four absorptions have been added.

(d(iv))[1]

Explain the splitting pattern for the absorption at $\delta = 1.2\,\text{ppm}$.

(d(v))[1]

The proton NMR spectrum of benzocaine dissolved in D$_2$O was recorded. Suggest how this spectrum would differ from the spectrum in (d)(ii). Explain your answer.

(e(i))[1]

Suggest the reagents used for step 1.

(e(ii))[2]

Suggest structures for compounds R and S and draw them in the boxes.

Worked solution & mark scheme

This 25-mark question has a full step-by-step worked solution and mark scheme. One marking point: Correct structure drawn

  • Full mark scheme, point by point
  • Step-by-step worked solution
  • Write your answer & get it marked instantly by AI