Question 18N.2.hl.TZ0.8
| Date | November 2018 | Marks available | [Maximum mark: 6] | Reference code | 18N.2.hl.TZ0.8 |
| Level | hl | Paper | 2 | Time zone | TZ0 |
| Command term | Draw, Predict, State, Suggest | Question number | 8 | Adapted from | N/A |
Carbon dioxide contributes significantly to global warming. It can be used as a raw material with methyloxirane to form polymers.
Suggest why the three-membered ring in methyloxirane is unstable.
[1]
angle between bonds is 60°/strained/smaller than 109.5° ✔
Draw two structural isomers of methyloxirane.
[2]
Any two of:
CH3COCH3 ✔
CH3CH2CHO ✔
CH2=CHCH2OH ✔
CH3OCH=CH2 ✔
Accept displayed or condensed structural formulas or skeletal formulas.
Accept CH(OH)=CHCH3 and CH2=C(OH)CH3.
State, giving a reason, whether methyloxirane can form cis-trans isomers.
[1]
no AND only one «axial/methyl/CH3» substituent «at the ring»
OR
no AND two «axial» substituents required «for cis/trans-isomers» ✔
Accept “no AND «O in the ring and» one carbon has two H atoms”.
Predict the chemical shift and splitting pattern of the signal produced by the hydrogen atoms labelled X in the 1H NMR spectrum of the polymer. Use section 27 of the data booklet.
[2]
Chemical shift:
3.7–4.8 «ppm» ✔
Splitting pattern:
doublet ✔