[andyman20]

Hi people..^^
I'm having an exam soon and i was wondering if you guys can help me out...^^
um.. i'm a bit confused on bondings in "water" topic.
the bondings i want to talk about are:

- polar covalent bonding
- dipole-dipole interactions
- hydrogen bonds
- dispersion forces
- ion-dipole interactions

polar covalent bonding ocurs between atoms that make up 8 electrons.

dipole-dipole forces are an attraction between negative pole and positive pole of atoms.

hydrogen bonding is a bond between hydrogen and nitrogen, oxygen or fluorine.

dispersion forces are temporary attraction between negative pole and positive pole of fluctuating atoms.

ion-dipole  is an interaction between a charged ion and a polar molecule(having dipole)

please post messages on what i am wrong. please tell me what i got right as well

thank you.

[Qazzian]

Alright, you're either right or close on all of them, here's where things are a bit off.

Dipole - Dipole - These aren't between poles of an atom, they're between poles of a bond in a molecule. If you have to elements with different electronegativity, one will have a more positive charge, and one will have a more negative charge. These are the poles that are used to attract other molecules.

Hydrogen Bonding - While it's true that these bonds involve Hydrogen and either Oxygen, Nitrogen, or Flourine, it's not quite how you said it. When you have a bond between H and these three elements (F,O,N), you end up with a strong dipole. For example, H-O-H (since you brought up water, we'll use that). Each bond is very polar, since O, N and F are all very electronegative. When you have the positive end of one of these bonds (the H) near the negative end of another bond (The O), they are attracted much the same way dipole dipole forces work.

Each H can Hbond to 1 Oxygen in water, and each O can H-bond to two H's, so each water molecule can H bond to 4 others. This is why water has sucha  high boiling point, high surface tension, and why it actually expands when it freezes.

You should not that all of the bonding you mentioned are intermolecular EXCEPT the Polar covalent, which is intramolecular.

and incase you're not sure what I mean: Intermolecular: Bond between two different molecules in a complex (solution, solid, whatever they happen to be in)

Intramolecular: Bonding of the atoms within a single molecule.

[andyman20]

Thank you for your reply
It gave me alot of *delete me*