Chemistry-Physical Changes and Intermolecular Forces

[Flip]

Hi everyone.

I have recently just started studying chemistry for my Junior year in High School. So you could say that I am a newbie at this.

I have small knowledge on the relationship between Intermolecular Forces and Physical changes. (Example: Boiling Point.)

So if the IMF of a molecule is high, would it take more energy(heat) to move it to a different state of matter? And if so how would the amount of energy be determined? How do you calculate the boiling point between 3 molecules?

Example:

46. Of the following substances,_____________ has the highest boiling point. (All numbers in the bottom are sub-scripts)

H20
CO2
CH4
Kr
NH3

A)H2O
B)CO2
C)CH4
D)Kr
E)NH3

Since H2O and NH3 have Hydrogen bonds I would assume that both those elements have the highest boiling points. Would more hydrogen atoms bonded on to the central atom mean that that molecule has the highest boiling point? If so then does that mean NH3 has the highest boiling point?

 

[GCT]

Does NH3 have a more hydrogen bond connections with respect to the individual molecule in an intermolecular "network." Also, which one has a higher electronegativity, Oxygen or Nitrogen?

 

[Flip]

Oxygen is more electronegative.