(a) Ethanoic acid, CH3CO₂H and trichloroethanoic acid, CCl3CO₂H, are both carboxylic acids. Ethanoic acid can be used to make ethanamide, CH3CONH2.

1. (a)Place these three compounds in order of acidity, starting with the least acidic. Explain your answer. least acidic < < most acidic[3]
2. (b)Methanoic acid, HCO₂H, and ethanedioic acid, HO₂CCO₂H, are two other carboxylic acids.
3. (b)(i)State which, if any, of ethanoic acid, methanoic acid and ethanedioic acid will react with Fehling's reagent.[1]
4. (b)(ii)State which, if any, of ethanoic acid, methanoic acid and ethanedioic acid will react with warm acidified manganate(VII) ions.[1]
5. (c)Ethanamide can be made from ethanoic acid in a two-step synthesis. ethanoic acid ---step 1---> A ---step 2---> ethanamide
6. (c)(i)Compound A contains chlorine. Give the structural formula and name of A. structural formula name[2]
7. (c)(ii)Suggest suitable reagents for steps 1 and 2. step 1 step 2[2]
8. (d)Compound A can also be used to make the amide CH3CONHC2H5. The proton NMR spectrum of the amide CH3CONHC2H5 in the solvent CDCl3 is shown. [Figure 6.1]
9. (d)(i)Explain why CDCl3 is used as a solvent instead of CHCl3.[1]
10. (d)(ii)Complete the diagram with the chemical shifts, δ, of the protons labelled in the CH3CONHC2H5 molecule. [Figure 6.2][2]
11. (d)(iii)State and explain how the proton NMR spectrum of the amide CH3CONHC2H5 differs when dissolved in D₂O rather than CDCl3.[2]
12. (e)The mass spectrum of the amide CH3CONHC2H5 includes a fragment ion with m/e value of 58. Give the molecular formula of this fragment ion. fragment ion with m/e value of 58 is[1]
13. (f)The amide undergoes the following reaction to produce diethylamine. CH3CONHC2H5 ---reagent B---> C2H5NHC2H5 diethylamine
14. (f)(i)Identify reagent B.[1]
15. (f)(ii)State the number of different absorptions in the carbon-13 NMR spectrum of diethylamine.[1]

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