Hydrogen Bonding of Molecules: NH3, H2O, CH4, CH3OH & CH3OCH3

[nhrock3]

1. NH3 ,NH3
2. H2O , NH3
3. CH4 ,NH3
4. CH4 ,CH4
5. CH3OH ,CH3OH
6. H2O ,CH3OH
7. CH3OCH3 ,H2O
8. CH3OCH3 ,CH3OCH3
9. CH3OH ,CH3OCH3

which one of those pair molecules could make hydrogen bonds?
i know i law
that H bonds with N O F
so its 1 2 3 5 6 7 8 9 pairs

but the book says 1 2 5 6 7 9

why??

 

[help4drdu]

3. CH4 ,NH3 CH4 is non polar unable to react with the polar NH3.
4. CH4 CH4 definity no polarity here and no functional groups so I can not see the H bonds anywhere and they are same molecule thus I think there is no reaction
8. CH3OCH3 ,CH3OCH3 same as 4

1. NH3 ,NH3 Very polar molecule thus H bonds from N to H due the extremely electronegative N. Note this is not a bond but merely a intermolecular force.
2. H2O , NH3 -H of H20 to N of NH3 and O of H20 to H of NH3 because both O and N are extremely electronegative thus creating polarity and thus in turn results in H bonds
5. CH3OH ,CH3OH - Hydroxy functional group (-OH) of ethanol are extremely polar thus electronegative thus they are able to form H bonds
6. H2O ,CH3OH - Hydroxy functional group(-OH)...
7. CH3OCH3 ,H2O - Hydroxy functional group(-OH),...
9. CH3OH ,CH3OCH3 Hydroxy functional group(-OH)...

I think it is because of they are all non-polar molecules thus unable to react N O F to produce H bonds. Because non polar molecules can not react with polar molecules and since N O F have extremely high electronegativity they are almost always polar molecules.
Erhh.. better ask someone better I am just a student at high school learned this stuff like couple months ago. I tried best sorry for any mistakes. =]

 

[Blueshift5]

I can confirm that the book is correct in stating that the pairs 1, 2, 5, 6, 7, and 9 can form hydrogen bonds. This is because these pairs involve molecules with hydrogen bonded to nitrogen, oxygen, or fluorine atoms. Hydrogen bonding occurs when a hydrogen atom is bonded to one of these highly electronegative elements, creating a strong dipole-dipole interaction with another electronegative atom (such as another nitrogen, oxygen, or fluorine atom). This results in a stronger intermolecular force and therefore, the ability to form hydrogen bonds. On the other hand, pairs 3, 4, and 8 do not involve hydrogen bonding because the molecules do not have a hydrogen atom bonded to nitrogen, oxygen, or fluorine. Instead, they have weaker intermolecular forces such as London dispersion forces. Overall, understanding the concept of electronegativity and the types of atoms involved in hydrogen bonding is important in determining which pairs of molecules can form hydrogen bonds.