[WESIDA]

well i've posted this question and i guess it got delted. here are how i tried to solve the problems, they are multiple choice so all i know is information on how to solve them, i have only listed the problems to give you and idea.
my knowing is that intermolecular forces is the the forces between molecules, and the smaller the molecules are the smaller the forces... iam not sure about this. my teacher did not do a good explaintion on this, and she gave us a very nice sheet full of these questions. so iam posting three diffrent kind of questions. you don't have to tell me the answer but iam just asking for help on information on them

Which of the following compounds should have the lowest boiling point temprature
A) CH3-Br B)CH3-Cl C)CH3-F D)CH3-H E)CH3-I

And the next question

Which Compound is expected to have the weakest intermolecular forces?
A)CH3-CH2-H
B)CH3-CH2-O-H
C)CH3-CH2-PH2
D)CH3-CH2-S-H
E)CH3-CH2-Se-H

And last question

Which one of the following listed compounds should have the highest vapor pressure at a given tempreature at which all these substances are in the liquid state?
A)CH3-CH2-H
B)CH3-O-CH3
C)CH3-CH2-CH2-CH3
D)CH3-CH2-CH3
E)CH3-CH2-S-H

For the first question i picked CH3-F because F is the smallest atom based on what i know now(it might be wrong)

for the second question i picked (A) because it has the smallet number of molecules
and the third question i had no clue what is going on

[WESIDA]

Please guys any hints, i have the test tomrow morning

[Skyline]

i don't know if this is going to help or not for your test tomorrow

Question #1
in order to find the compund with the lowest boiling temperature, you are correct about the concept, but you need to look more carefully at the answer choice, there are one answer that has lower molecular mass than CH₃Br
which of the compound listed is the smallest in size?? CH₃H

Question #2
the weakest intermolecular force is : Van de Waals (dipole-dipole) force, then ionic bond, covalent bond, and strongest is non-covalent bond
from the choices CH₃-CH₂-H seem to be the weakest of all
i'm not too sure about this one, you might want to look more into it.

Question #3
partial pressure and temperature has an inversly proportional relationship
meaning as pressure increases, it requires a lower temperature to boil
that is how the pressure cooker work  
with the concept from quetsion #1 and the relationship between temp and pressure
i'm sure you can figure out the answer for this question.

Good luck with your test!!!

enzymatic clothing

[WESIDA]

hey thanks alot  . too bad i read the question after the test was given. but we have another comprehinsive final. the teacher gave us a review sheet with one of the same questions i listed.
thanks again