Intermolecular Forces

Intermolecular Forces

Vocabulary

• Dipole Interactions: Intermolecular forces resulting from the attraction of oppositely charged regions of polar molecules

• Dipole: A molecule that has two poles, or regions, with opposite charges

• Dispersion forces: Attractions between molecules caused by the electron motion on one molecule affecting the electron motion on the other through electrical forces

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What are Intermolecular Attractions

• Weak attractions between molecules

• Weaker then Ionic and covalent bonds

• Responsible for determining whether a compound is a solid liquid or gas

Van der Waals Forces

• The weakest force between molecules

• Includes both dipole interactions and dispersion interactions

• Found between both polar and non-polar bonds

• The only forces found in non-polar molecules

Dipole-Dipole Interactions

• When two dipole molecules interact with each other through space.

• The partially negative portion of one polar molecule is attracted to the partially positive portion of a second molecule.

• Can not happen between non-polar molecules

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Hydrogen Bonds

• Attractive forces in which a hydrogen covalently bonded to a very electronegative atom

• Oxygen, Nitrogen and Fluorine

• Hydrogen- The only chemically reactive element with valence electrons that are not shielded from the nucleus by other electrons.

• The strongest intermolecular forces

Multiple Choice

What is the strongest intermolecular forces in the molecule?

• Van der Waals Forces

• Hydrogen bonds

• Dispersion Forces

Multiple Choice

What is the strongest intermolecular forces?

• Hydrogen bonds

• Van der Waals Forces

• Dipole-Dipole

Multiple Choice

Is the molecule polar or non-polar and what is the strongest intermolecular forces?

• Polar- Van der Waals Forces

• Non-Polar- Van der Waals Forces

• Polar- Dipole-Dipole

• Non-Polar- Dipole-Dipole

Multiple Choice

Which molecule has the strongest intermolecular forces?

• H-F

• H-Cl

• Br-Br

• Cl-I

Multiple Select

Which of the following molecules would have Van der Waals Forces

• CH₄

• SCO

• PCl₃

• SO₂