CHEM. MC - Ans.fyi 參考答案

CHEM. MC

Kyy010203

2010-12-11 12:47 am

Question 15:Which of the following statements about addition polymers are correct?(1) They are formed from monomers with unsaturated bonds.(2) They are thermoplastics.(3) They are biodegradable.A. (1) and (2) onlyB. (1) and (3) onlyC. (2) and (3) onlyD. All of them Question 16:Which of the following statements about addition polymers are correct?(1) They do not decolourize bromine water.(2) They have a low tensile strength.(3) They are insoluble in water.A. (1) and (2) onlyB. (1) and (3) onlyC. (2) and (3) onlyD. All of them Question 20:Which of the following statements about polythene are correct?(1) Polythene decomposes to give ethene on burning.(2) Polythene is acid-resistant.(3) Polythene is commonly used to make plastic bag (used in supermarkets).A. (1) and (2) onlyB. (1) and (3) onlyC. (2) and (3) onlyD. All of them Question 28:Which of the following statements about polyvinyl chloride is incorrect?A. It is made from chloroethane.B. It is an addition polymer.C. It is acid-resistant.D. It can be used to make water pipe.

回答 (1)

己式庚辛

2010-12-11 7:14 am

✔ 最佳答案

15. A
without unsaturated bonds, addition reaction cannot take place.
very few addition polymers are thermosets.
whether they're biodegradable, it depends on presence of side branches. polypropene has a lot of side branches, so it's non-biodegradable; yet it's addition polymer.

16. B
after polymerization, all unsaturated bonds are removed. only single bonds are left. thus it cannot decolorize bromine water via addition reaction.

20. C
on burning, it is oxidized to give carbon dioxide and water, with some carbon monoxide and carbon. NO of little free ethene is given.

28. A
C=C bond is needed, where chloroethane does not possess one. chloroethene is used instead.

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