Concepts: Types of Bonds Among Liquids and Solids

1. Concepts:Types of Bonds Among Liquids and Solids By: I Schnizzle

2. Overview • In this powerpoint I’ll be talking about the types of bonds that liquids and solids can make depending on the type of compound they are. • There are three major types of intermolecular forces: Dipole-dipole Forces, London Dispersion Forces, and Hydrogen Bonds.

3. Intermolecular Forces • Intermolecular Forces are attractive forces between molecules. • Intramoecular Forces are forces that hold atoms together within a molecule. • These two forces are very often confused with one another since they sound similar but just remember that inter is between will intra is within so naturally intra will be stronger than inter.

4. Intermolecular Forces:Van der Waals Forces • There are two types of Van der Waals Forces and these are Dipole-Dipole and London Dispersion forces. • The difference between these two types of forces is that Dipole-Dipole involves neutral, polar molecules. • The forces between the positive and negative ends of a molecule are held together with a dipole-dipole (d-d) force.

5. Intermolecular Forces:Van der Waals Forces Cont’ • Since polarity is involved with d-d forces the greater the polarity the more the d-d attraction creating such things as higher melting and boiling points, even though the attractions are relatively weak within d-d forces. • Substances that experience D-D forces are usually gases or liquids at room temperature. • London Dispersion Forces are those that involve neutral, nonpolar molecules.

6. Intermolecular Forces:Van der Waals Forces Cont’ • These London Dispersion (L-D) forces are very weak in nature and occur because of the random shifting and motion of electrons on atoms within a given molecule. • Since the L-D forces rely on electrons there can be at some instances a split second of time where a dipole moment occurs such as when more electrons are on one side of an atom than the other. • Also because of the reliance on electrons L-D forces are naturally stronger when there are more electrons on an atom.

7. Intermolecular Forces:Van der Waals Forces Cont’ • These L-D forces are very weak however and so even though they might be stronger with the more electrons there are their melting and boiling points are still very low. • Finally, since these points are so low these substances that experience L-D forces are usually gases at room temperature.

8. Hydrogen Bonds • Hydrogen bonds are the last major type of Intermolecular forces and are by far the strongest. • Like d-d forces hydrogen bonds involve the positively charged end of one molecule to be attracted to the negatively charged side of another molecule. • The difference among the two forces is that the negatively charged end of the other molecule is one that is extremely electronegative such as N,O, or F.

9. Hydrogen Bonds • The reason that they Hydrogen bonds are that much stronger than their similar d-d bonds is that once the H atom releases its lone electron to the bond the nucleus is left unshielded. • This causes the bond to be very strong and allows for substances that have hydrogen bonds like water to have higher melting and boiling points than other substances that have d-d forces instead.

10. Conclusion • Dipole-Dipole= forces between neutral, polar molecules. Not very strong • London Dispersion forces= forces between neutral, nonpolar molecules. Weaker than the Dipole-Dipole forces. • Hydrogen Bonds- forces like Dipole-Dipole except the negatively charged end of one molecule is very electronegative like N,O, or F. Strong bond since nucleus is left unshielded.

11. And that’s all she Wrote Shout out to my juniors: Canada, Dani, Tony, Mike, and James Hi to you to Kaiye (if I spelled that right) and of course SANDRA OH BABY!??!?!