Chemistry 9701 · AS & A Level · Analytical techniques

Analytical techniques — practice question

Compound T is produced in a three-stage synthesis.
(a)[1]

During stage 1, phenylethanoic acid is treated with a suitable reagent to produce compound R. Suggest a suitable reagent for stage 1.

(b(i))[1]

State the name of the functional group produced in stage 2.

(b(ii))[1]

Identify the second product formed in stage 2.

(c(i))[1]

State the formula of a suitable reagent used in stage 3.

(c(ii))[1]

Name the reaction type taking place in stage 3.

(d(i))[1]

Calculate the relative abundance of the $\text{M}+1$ peak in the mass spectrum of ethylamine, given that the relative abundance of the molecular ion peak is 62.

(d(ii))[2]

The mass spectrum of compound T shows a number of fragments. Two of the fragment peaks have $m/e$ values of 29 and 91. Draw the structures of the ions that give rise to these peaks.

(e(i))[1]

Identify the proton or protons with a chemical shift $(\delta)$ between 6.0 and 9.0.

(e(ii))[1]

Identify the proton or protons whose peak disappears after $\text{D}_2\text{O}$ is added.

(e(iii))[1]

Identify the proton or protons whose peak is observed as a triplet.

(e(iv))[1]

Identify the proton or protons with the lowest chemical shift $(\delta)$.

Worked solution & mark scheme

This 12-mark question has a full step-by-step worked solution and mark scheme. One marking point: \mathrm{PCl_3} or \mathrm{PCl_5} or \mathrm{SOCl_2}

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