Q1M5 - General Types of Intermolecular Forces

What is true about intermolecular forces?

• They are strong bonds that form between atoms of molecules.

• Substances can form more than one but one will predominate.

• They are stronger than the intramolecular forces between atoms.

• There is a vague relationship between intermolecular forces and bulk

  properties.

Ion-dipole interaction results from the

• Attraction between an ion and a polar molecule.

• Repulsion between a dipole and another dipole.

• Repulsion between a polar with a nonpolar molecule.

• Attraction between a polar with another polar molecule.

Why are dispersion forces high in molecules with great number of electrons?

• The electron distribution of big molecules is easily polarized.

• The nucleus in the molecules has greater effective shielding effect.

• The electrons move freely around the nucleus resulting to greater energy.

• The electrons in the molecules can easily jump from one orbital to

  another.

What are considered van der Waals forces of attraction?

• ion-induced dipole; dipole-dipole; London dispersion forces

• dipole-dipole; dipole-induced dipole; London dispersion forces

• London dispersion forces; ion-induced dipole; dipole-induced dipole

• dipole-induced dipole; ion-induced dipole; London dispersion forces

Distinguishing characteristic of London dispersion forces

• There is instantaneous dipole that influences neighboring substances to gain dipoles.

• There is permanent (-) and (+) ends that participate in electrostatic attractions.

• The electron cloud of the atoms are evenly distributed around the nucleus.

• The atoms of two neighbouring molecules participate in give and take of electrons.

How does dipole-dipole interaction happen?

• Polar molecules shift electron density that gives rise to neutral substances.

• The electron distribution in the polar molecules is distorted that results to (-) and (+) poles.

• Polarization of big nonpolar molecules brings about the formation of permanent (+) and (-) charges.

• The (-) and (+) ends of one polar molecule align themselves to the (+) and (-) ends of another polar molecule and attract each other.

During ion-dipole interactions, the cation causes the

• repulsion of charges among the molecules.

• distortion of the electron distribution in the dipole.

• attraction of the (-) ion to the (+) end of a permanent dipole.

• formation of (+) ions that are attracted to the permanent dipole.

H-bonding forms when the substances involved are polar and have molecules with

• H-atoms attached to O, N, F.

• C-atoms attached to O, N, F.

• central atoms with O, N, F as attached atoms.

• unshared pair of electrons in the central atom.

Which ions will result to higher ion-dipole interactions?

• anions

• divalent

• cations

• monatomic

What Intermolecular forces are present in the following species?

CH4