Draw line structures for the cis and trans configurations of CH3CH2CH=CHCH3.

See attached picture.

Explanation:

Hello,

In this case, on the attached picture you will find the required line structures for the cis and trans configurations of the given compound (2-pentene). Take into account for the cis that the adjacent carbons to those having the double bond remain in the same plane, whereas for the trans one, the adjacent carbons remain in a different plane.

Regards-

c. heat could easily travel through the molecules in the air and escape/enter the flask. removing the air slows down the heat transfer.