Name Date Class 18.3 Plastics and Other Polymers Study Guide CHAPTER Copyright © Glencoe/McGraw -Hill, a division of The McGraw -Hill Companies, Inc. Use with text pages 648 – 661 18 Use each of the terms below just once to complete the passage. addition reaction monomer thermoplastic condensation polymer thermosetting cross-linking Polyethylene is a synthetic material used for many different purposes, including the manufacturing of milk jugs and plastic beakers. The repeating unit, called a (1) , which forms polyethylene, is ethylene. Many hundreds or thousands of ethylene molecules combine in a reaction known as a(n) (2) , in which double bonds are broken when the repeating units combine. Because it is made of so many repeating units, polyethylene is an example of a(n) (3) . In polyethylene, the molecules are arranged in a long, linear sequence. Such materials are usually (4) , meaning that they tend to melt or soften when heated. Other polymers do not melt when heated and are called, therefore, (5) plastics. One reason that some polymers tend not to melt when heated is that their molecules undergo (6) , which tends to make the material more rigid. Other polymers are formed in a chemical reaction known as (7) during which a small molecule such as water is eliminated during the reaction. Place a T for true or an F for false on the blank for each of the following statements. Change the underlined word or phrase in each false statement to make it true. Write your correction on the blank. 8. Every polymer includes repeating units called monomers. 9. Teflon is a naturally-occurring polymer of tetrafluoroethylene. 10. The properties of a polymer are exactly like those of the monomer of which it is formed. 11. DNA, protein, and silk are examples of naturally-occurring polymers. Chemistry: Concepts and Applications Study Guide, Chapter 18 75 Name Date Class In each of the following statements, select the letter of the word or phrase that best completes the sentence. 16. A polymer that was discovered accidentally is . a. nylon b. polyethylene c. Teflon d. rubber 17. An example of a naturally occurring polymer is . a. polyethylene b. cellulose c. Teflon d. nylon 18. The monomer from which cellulose and starch is made is . a. glucose b. ribose c. cyclohexane d. benzene 19. Whether a monomer will undergo addition polymerization or condensation polymerization depends on . a. the size of the molecule b. the molecule’s structure c. whether the molecule is aromatic d. whether the molecule occurs naturally or not 20. When two polymer chains link to each other, the process is known as . a. addition b. condensation c. cross-linking d. chain-linking 76 Chemistry: Concepts and Applications Study Guide, Chapter 18 Copyright © Glencoe/McGraw -Hill, a division of The McGraw -Hill Companies, Inc. 12. Cellulose and starch are made of the same monomer. 13. Addition reactions cannot occur between double-bonded molecules. 14. During vulcanization, sulfur is added to liquid latex to make a more flexible product. 15. Polyethylene is an example of a thermoplastic polymer.