2. Low-density polyethylene, used to make plastic films, is made by the radical polymerization of ethene, and is one of
the hardest plastics to recycle. It gets its name
A. from the process by which it's polymerized.
B. because of the way the chains pack like spaghetti, close
and tight.
C. from the spaces left between chains when the polymer is
formed.
D. because it's strong but flexible.

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.

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.

first, consult an activity series chart to determine if al is more reactive than fe. it is, so it will replace the fe. now, one can continue with the problem.

next, make sure you have a correctly balanced equation.

3feo + 2al ==> 3fe + al2o3

now, determine which reactant (feo or al) is in limiting supply.

moles feo present = 125 g x 1 mole/71.8 g = 1.74 moles

moles al present = 25.0 g x 1 mole/26.98 g = 0.927 moles

since from the balanced equation, it take 3 mol feo for every 2 mol al, al will be limiting.

you can determine this simply by dividing moles of each by their coefficient in the balanced equation. for example: 1.74/3 = 0.58 and 0.927/2 = 0.464. al is less, so it is limiting.

finally, using the stoichiometry in the balanced eq. determine mass of fe that can be produced from 0.927 moles of al.

0.927 moles al x 3 moles fe/2 moles al x 55.8 g/mole = 77.6 g

8 m/s because for him to get the same amount of energy as ray is putting out, bobby, who weighs half as much as ray, needs to run twice as fast.