A short fragment of a polymer chain (two repeat units, end groups shown) is drawn. Which natural polymer does it represent?

ANeoprene
BTeflon
CNatural rubber (cis-1,4-polyisoprene)
DGutta-percha (trans-1,4-polyisoprene)

Answer: C

Each repeat unit has a C=C in which the two chain carbons lie on the same side (cis, Z), and a methyl on the double-bond carbon. This is cis-1,4-polyisoprene, natural rubber. Gutta-percha is the trans isomer, neoprene carries Cl on the double bond and Teflon has no C=C.

Practice Polymers More on Geometry, tacticity and crosslinking in drawn chains

Previous questionNext question

More questions on Geometry, tacticity and crosslinking in drawn chains

A short fragment of a polymer chain (four repeat units, end groups shown, methyl groups drawn with wedges and dashes) is drawn. Which descri... JEE Main level
A short fragment of a polymer chain (five repeat units, end groups shown, substituents drawn with wedges and dashes) is drawn. Which stateme... JEE Main level
A short fragment of a polymer chain (four repeat units, end groups shown, substituents drawn with wedges and dashes) is drawn. Counting each... JEE Advanced level
A short fragment of a polymer chain (three repeat units, end groups shown) is drawn. Compared with the cis isomer of the same constitution (... JEE Main level
A short fragment of a polymer chain (three repeat units, ethyl-type end groups shown) is drawn. Sulfur vulcanisation proceeds mainly through... JEE Advanced level
A short fragment of a hydrocarbon rubber chain (two repeat units, end groups shown) is drawn. Select all correct statements about its vulcan... JEE Main level