Which compound can form a condensation polymer on its own, without a second monomer?
CH3CH2COOH\mathrm{CH_{3}CH_{2}COOH}CH3CH2COOH
HOCH2CH2COOH\mathrm{HOCH_{2}CH_{2}COOH}HOCH2CH2COOH
HOCH2CH2OH\mathrm{HOCH_{2}CH_{2}OH}HOCH2CH2OH
CH2=CHCOOH\mathrm{CH_{2}{=}CHCOOH}CH2=CHCOOH
63 exam-style questions on OCR GCSE Chemistry 6.2 Organic chemistry, covering 6.2.1 Crude oil and fractional distillation, 6.2.2 Cracking and dependence on hydrocarbons, 6.2.3 Functional groups and homologous series, 6.2.4 Reactions of alkanes, alkenes and alcohols, 6.2.5 Addition polymerisation and repeat units, 6.2.6 Naturally occurring polymers, 6.2.7 Chemical cells and fuel cells, and 6.2.8 Condensation polymerisation and how to make one. Each one has a worked solution and a mark scheme showing where the marks go.