Question

${\text{Buna - N}}$ is used in making oil seals and tank linings, etc. because:
A: It is resistant to the action of lubricating oil and organic solvents
B: It is more elastic than natural rubber
C: It can be stretched twice its length
D: It does not melt at high temperatures

Answer 1

Hint: ${\text{Buna - N}}$ is nitrile rubber. It is also known as $NBR$ or acrylonitrile butadiene rubber. This is a synthetic rubber. ${\text{Buna - N}}$ is a copolymer. Polymers are the materials that are made up of long and repeating chains.

Complete step by step answer:
${\text{Buna - N}}$ is nitrile rubber. It is also known as $NBR$ or acrylonitrile butadiene rubber. This is a co-polymer. Copolymers are the polymers that are made from more than one species of monomers. Co-polymers are called biopolymers when they are derived from two species of monomers. ${\text{Buna - N}}$ is a synthetic rubber.${\text{Buna - N}}$ is resistance to oil, fuel and other chemicals. It does not react with oil. Due to this resistance of ${\text{Buna - N}}$ to oils, fuels and other chemicals it is used in making oil seals and tank linings etc.
So, the correct answer is option A.
Additional information: Polymers are the materials that are made up of long and repeating units of monomers. These are of two types, natural polymer and synthetic polymer. Natural polymers are those which are obtained naturally. These polymers are present in nature while synthetic polymers are not present in nature. These polymers are man-made. Some common examples of natural polymers are, nucleic acids, proteins etc. and of synthetic polymers are polyethylene, nylon, polyester, Teflon etc.

Note:
Based on the arrangement of chains of co-polymers these are divided in two categories, linear polymers and branched polymers. Linear polymers are the polymers which consist of only one single chain of polymers while branched polymers are those which contain one main chain and one or more side chains.