Question

2. Low-density polyethylene, used to make plastic films, is

Answer 1

Answer: it gets its name (from the process by which it's polymerized). Therefore the correct option is A.

Explanation:

Polyethylene is a type of plastic which is made by the polymerization of its monomers (ethene). The most common monomers are derived from petrochemicals. The monomers simply join together to form the polymers which has the same empirical formula as the monomer, but is of a higher molecular mass.

There are two main types of polyethylene, these include:

--> Low density polyethylene: when ethene is subject to a high temperature of about 250°C and pressure above 1500atm, together with traces of oxygen ( as an initiator), it polymerizes to polyethylene. The polyethylene obtained by the above method is called a low density polyethylene. It has the most long- and short-chain branching of any form of polyethylene, resulting in its lower density. Therefore its name is gotten from the process by which it's polymerized

--> High density polyethylene: this is prepared at a lower temperature and pressure by using catalysts.

Answer 2

Answer:

from the spaces left between chains when the polymer is

formed.

Explanation:

Polyethylene polymer may be of high or low density. Whether the polymer is of high or low density depends on the arrangement of the polymer chains.

If the polymer chains are close together such that the resultant polymer is crystalline with chains packed closely, we have high density polyethylene.

On the other hand if the chains are not close together and there are spaces left between chains when the polymer is formed, then we have low density polyethylene.

Hence, low density polyethylene gets its name from the spaces left between chains when the polymer is formed.