Weekly topic: 5 Wealth points for those who answer correctly, 2 Wealth points for participation； Question 152
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Multiple choice: PHB plastic is an environmentally friendly plastic that can be degraded by microorganisms; its structural formula is. Which of the following statements about PHB is incorrect? ( ) A. PHB is a type of polyester. B. The monomer of PHB is CH3CH2CH(OH)COOH. C. The degradation products of PHB may include CO2 and H2O. D. PHB is obtained through addition polymerization. Answer: D. Hint: Based on its structure, it can be determined that PHB is a polymer; since one of the units in its chain is an oxygen atom and the other is a carbonyl group, it is a polymer formed by esterification reactions between identical molecules, meaning it is a polycondensation reaction (with the formation of small molecules).
Answer: D. Based on its structure, PHB can be identified as a polymer compound; since one of the linkages in its chain is an oxygen atom and the other is a carbonyl group, it is determined to be a polymer formed through an esterification reaction between identical molecules, which means it is a polycondensation reaction (with the formation of small molecules).
D. PHB is produced through polyaddition reactions. D. PHB is produced through polyaddition reactions
PHB plastic is an environmentally friendly plastic that can be degraded by microorganisms, and its structural formula is as follows. The incorrect statement regarding PHB below is (C)
PHB plastic is an environmentally friendly plastic that can be degraded by microorganisms, and its structural formula is as follows. The incorrect statement regarding PHB is (D). A. PHB is a type of polyester. B. The monomer of PHB is CH3CH2CH(OH)COOH. C. The degradation products of PHB may include CO2 and H2O. D. PHB is produced through polyaddition reactions
D. PHB is produced through polyaddition reaction
D, -------- (PHB should be produced through a polycondensation reaction)
D. PHB is produced through polyaddition reaction.
A. The substance obtained by connecting the two half-keys in the link is an ester; therefore, PHB plastic is a type of polyester, so A is correct； B. The two half-keys in the chain link are combined to form an ester; thereafter, a hydroxyl group is added to the carbonyl group of the chain link, and a hydrogen atom is added to the oxygen atom of the same chain link. In this way, the monomer of PHB is obtained. Therefore, the monomer of PHB plastic is CH3CH2CH(OH)COOH, so B is correct ； C. PHB plastic contains carbon, hydrogen, and oxygen as its elements; therefore, its degradation products may be CO2 and H2O, so C is correct ； D. Since not all atoms in the linkages are carbon atoms, and it is not produced through a polyaddition reaction but rather as a product of a polycondensation reaction, therefore D is incorrect ； Therefore, the answer is D
D. PHB is produced through polyaddition reaction