Question

Polypropylene is formed from the propylene monomer. Assuming an appropriate catalyst, which of the following shows the formation of the polymer?

1) CH₃-CH=CH₂ + CH₃-CH=CH₂
2) CH₃-CH=CH₂ + CH₃-CH₂-CH=CH₂
3)H₃-CH₂-CH=CH₂ + CH₃-CH₂-CH=CH₂
4) CH₃-CH₂-CH=CH₂ + CH₃-CH=CH₂

Answer 1

Polypropylene is formed by the polymerization of identical propylene monomers (CH₃-CH=CH₂). Option 1, which shows the reaction of CH₃-CH=CH₂ with another unit of CH₃-CH=CH₂, correctly represents the formation of polypropylene.

Step-by-step explanation:

The formation of polypropylene from the propylene monomer involves a chain-growth polymerization process. Propylene has the chemical formula CH₃-CH=CH₂. For polypropylene to form, propylene monomers must link together by opening their double bonds and connecting to other propylene units in a repeating fashion. Looking at the options, the correct formation of polypropylene would include the repetition of the same monomer unit.

Option 1, CH₃-CH=CH₂ + CH₃-CH=CH₂, is the correct choice since it involves the addition of identical propylene (CH₃-CH=CH₂) monomers. When polymerized in the presence of an appropriate catalyst, each propylene monomer unit joins together at the double bond to create the long-chain polypropylene polymer. Option 2 incorrectly combines two different alkenes, and Options 3 and 4 also involve incorrect combinations of alkenes, which would not lead to polypropylene. Therefore, Option 1 demonstrates the correct sequence for forming polypropylene.