AP CHEM QUESTION...PLEASE HELP!!!!(RECOMMENDED FOR THOSE WHO ARE HIGHLY EDUCATED IN

  • Thread starter Thread starter edwardsgrl92
  • Start date Start date
E

edwardsgrl92

Guest
THIS FIELD)? CH3CH2OH boils at 78 degrees celsius and CH3OCH3, boils at -24 degrees celsius, although both compounds have the same composition. This difference in boiling points may be attributed to a difference in which of the following (explain the reasoning for your selection):
a. molecular mass
b. density
c. specific heat
d. hydrogen bonding
e. heat of combustion

***PLEASE TELL ME YOUR SOURCE!!! I REALLY NEED HELP WITH THIS, SO PLEASE HELP!!!!!!!!!!!!!!!!!
 
gotta be hydrogen bonding. CH3CH2OH is like:

CH3-CH2-OH === OH-CH2-CH3

The === represents the hydrogen bonding between oxygen and hydrogen atoms (hydrogen bonding is a strong inter-molecular bonding between hydrogen and oxygen/some other similar atoms, which you can look up in wikipedia or something). But in a CH3OCH3 atom:

CH3-O-CH3

There is no room for hydrogen bonding, so the attraction between molecules is weaker. So, in ethyl alcohol (the first one), the stronger attraction between the molecules means it is harder for them to break free and thus it requires a higher temperature for it to boil, whereas the weaker bonding between the molecules in dimethyl ether (the second one) causes it to have a lower boiling point.
 
Back
Top