Halogen compounds

8(a)  chlorobenzene is less reactive than chloroethane OWTTE 2  p-orbital / lone pair on Cl will overlap / delocalise into the ring  due to partial double C-Cl bond OWTTE OR C-Cl bond strengthened (more) Any two [1], all three [2] 8(b)(i) ethyl 3-chloropropanoate 1 © UCLES 2023 Page 16 of 19 8(b)(ii) W 4 X O OH HO ONa Y Z O O HO H N 2 OH O O 4  [1] for each structure 8(b)(iii) M1 step 1 NaCN / KCN in ethanol (heat) 2 M2 step 2 H + Ni / H + Pt ALLOW LiAlH 2 2 4 8(c)(i) (because solvent / D / CDCl ) doesn’t give a signal / peak / absorption ORA 1 3 © UCLES 2023 Page 17 of 19 8(c)(ii) 4 chemical splitting number of 1H atoms environment of proton shift δ / ppm pattern responsible for the peak 1.2 alkyl / alkane / (R-)CH triplet 3 (3) 2.8 alkyl next to C=O / triplet 2 CH C=O (2) 3.7 alkyl next to triplet 2 electronegative atom / CH -Cl (2) 3.9 alkyl next to quartet / 2 electronegative atom / quadruplet CH -O (2) Any three [1], any six [2], any nine [3], all twelve [4] 8(c)(iii) ( = 3.9) three H on neighbouring / adjacent C / it’s next to a CH 1 3 © UCLES 2023 Page 18 of 19