notes 4 - Chapter11 Intermolecul

Info icon This preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 11 Intermolecular Forces Intra molecular bonds are strong covalent bonds responsible for holding the  atoms of a molecule together Intra molecular means  within  the molecule Inter molecular bonds are weak bonds  between  molecules Why are Intermolecular Bonds important? Intermolecular forces determine whether a compound is a solid, liquid,  or gas Melting and Boiling points are determined by intermolecular forces Solubility is partially determined by intermolecular forces Other physical properties, such as surface tension and viscosity, are  determined by intermolecular forces Types of Intermolecular Forces Ion-Dipole Forces o Ion-dipole forces require an  ion  and a  polar molecule o The polar molecule contains a dipole (a + pole and a – pole) o The force arises from the + - electrostatic attraction. This is a  coulomb force o Ion-dipole forces occur most commonly when ions are dissolved  in polar solvents Dipole-Dipole
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
o Two dipoles can produce an attractive dipole-dipole force when  they align so that the + part of one molecule attracts the – part  of another London Dispersion Forces o London dispersion forces are also called  van der Waals forces o All atoms and molecules have this type of force o A charge or dipole is not required o Temporary fluctuations in time of electron orbitals create  instantaneous dipoles o In one instant, they exist; in the next, they are gone o A dipole on one atom induces (creates) a dipole on an adjacent  atom o The two dipoles are oriented in opposite directions. This creates  a temporary attractive intermolecular force (dipole-dipole force) o When averaged over time, all of these random fluctuations  create a net attractive force o The net force is called a  London Dispersion Force o Trends for Dispersion Forces The larger the atom or molecule, the larger the  fluctuations of the orbital
Image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern