Where would you expect to isolate molecules in a petroleum ...

[shofmannx20]

Where would you expect to isolate molecules in a petroleum fractionating tower that have the strongest intermolecular forces?
 
  A) near the bottom
  B) near the top
  C) near the middle
  D) Fractional distillation takes advantage of molecular weight.
  E) Fractional distillation takes advantage of the number of isomers.

Question 2

Why does ice form at the surface of a body of fresh water instead of at the bottom?
 
  A) Initial freezing requires the presence of air in order to form the ice lattice, thus the surface water will become solid first.
  B) Intermolecular forces are greater at the surface allowing the surface molecules to form the solid phase more quickly.
  C) Water near the freezing point of 0C is less dense than warmer water, and the colder water will float on the warmer water. This allows ice to form at the surface.
  D) All of the above are true.

[yeungji]

Answer to Question 1

A

Answer to Question 2

C

[shofmannx20]

Thank you!

[yeungji]

Always glad to help...