[Samlxo]

I was absent the day Intermolecular forces were taught in class, so I'm having some difficulty fully understanding each force.

For each of these forces

• LDF
• DDF
• H-Bonding
• Ionic
• Covalent Network
• Metallic

I would appreciate help understanding the type of elements, the type of chemical bonding, molecular polarity, phase at room temperature, type of solid, and relative ranks of density, boiling point, vapor pressure, and viscosity involved with each force.

I know that with DDF and H-bonding, the molecular polarity is polar (correct?) as well as thar H-bonding occurs with either N, O, or F.
I know LDF is the weakest of the forces, next comes DDF, H-Bonding, Ionic Bonding, Covalent Network, and then the strongest metallic bonding.

Also, I believe that the higher the IMF, the higher the boiling point. The higher the IMF, the higher the viscosity and the higher the IMF, the lower the vapor pressure.

But I would like to know each of those circumstances for each force so I can study and be prepared for my test! Thanks in advance

[Corribus]

You need to narrow your question. For something so broad, you should read about this topic in a textbook.

[Samlxo]

You need to narrow your question. For something so broad, you should read about this topic in a textbook.

I was reading about IMF in my Zumdahl last night, but i am still having trouble understanding it all.

[Corribus]

Be that as it may, you can't just say, "I am having trouble understanding chemistry. Please explain it to me."  You need to ask a focused question that targets your point of confusion.  This will help you as much as it will help us.

[Samlxo]

Be that as it may, you can't just say, "I am having trouble understanding chemistry. Please explain it to me."  You need to ask a focused question that targets your point of confusion.  This will help you as much as it will help us.

I think my biggest problem is understanding what type of solid goes with which IMF. I'd imagine the ionic solids would occur in an ionic bond, but as for the others, I am unsure.

[Nicho55]

LDF forces arise from temporary opposite charges forming on different molecules. This is because of electron movement within the molecules: as the electrons in one molecule randomly move to one end, causing a dipole (+ve at one end, -ve at the other), the repulsion causes the electrons in a neighbouring molecule to move accordingly. These are the weakest intermolecular force.

 http://mrjdfield.edublogs.org/files/2013/11/instantaneous-dipole-instantaneous-induced-dipole-illustration-13ofycm.gif

DDF are like LDF in that they are due to dipoles, but in this case the dipoles are permanent, not spontaneous or temporary like in LDF. This is due to electronegativity of elements in molecules. For example, in ICl, Cl is more electronegative than I, so withdraws electron density towards itself, causing a permanent dipole to arise on the molecule, that is, the Cl will posses a small (or delta) -ve charge and the I will posses a small (delta) +ve charge. This leads to the interaction of molecules as they attract each other.

H-Bonding is caused by a delta- positive H on one molecule interacting with a lone pair of electrons on another molecule. These are stronger than the previous two.

http://upload.wikimedia.org/wikipedia/commons/thumb/b/b5/Hydrogen-bonding-in-water-2D.png/800px-Hydrogen-bonding-in-water-2D.png

Ionic: forms between a metal and non-metal. The non-metal wants to gain an electron to have a full outer shell. The metal wants to lose an electron to have a full outer shell. So, the metal 'gives' an electron, or more, to the non metal, resulting in two oppositely charged ions, which then attract each other. The larger the charges on the ions, the stronger the bond. Every bond in an ionic compound is ionic i.e. ionic lattices are formed, such as NaCl. These have incredibly high melting points due to the large number of strong ionic bonds which must be broken. Ionic bonding isn't really an intermolecular force, therefore, as it exists between ions, not molecules.

Covalent: two atoms share electrons to obtain a full outer shell. The nuclei in the atoms are mutually and simultaneously attracted to the shared electron pair, resulting in a very strong bond. Again, this isn't  an IMF.

Metallic: metal atoms lose electrons when in a metallic structure. This gives a 'sea' of delocalsied electrons and +ve ions. The +ve ions are attracted to the electrons, and vice versa, binding the metal ions together. The more delocalised electrons there are, the stronger the metallic bonds. Not an IMF.

http://www.bbc.co.uk/schools/gcsebitesize/science/images/gcsechem_60.gif

I hope this helps. I'ts difficult to give a full explanation of everything, but at least i tried harder than Corribus. Any questions let me know.