Part 18 - Forces of Attraction

• ionic bond

• covalent bond

under Intramolecular forces of attraction (2)

intramolecular

“within molecules”

intramolecular

“between molecules”

ionic bond

• transfer of electrons

  • between metals and nonmetals

Metal

observes LEORA

nonmetal

observes GEROA

covalent bond

• sharing of electrons

• between nonmetals and nonmetals

unequally

polar covalent electrons are shared _____

equally

nonpolar covalent electrons are shared _____

partially negative

atom with the higher electronegativity pulls the electron close to itself, gaining a slight (-) charge

partially positive

atom with the lower electronegativity has the electron pulled away, leaving it with a slight (+) charge

• ion-dipole

• ion-induced dipole

• induced dipole - induced dipole (London dispersion force)

• dipole - induced dipole (Debye Induction force)

• dipole - dipole (Keesom Orientation force)

  • hydrogen bond

under intermolecular forces of attraction (5)

hydrogen bond

• attraction between a hydrogen atom attached to a highly electronegative atom and a nearby electronegative atom in another molecule

• special kind of dipole-dipole interaction

• F

• O

• N

hydrogen atoms in a hydrogen bond are usually attached to (3)

ion

contains unequal number of protons and electrons

dipole

contains 2 charges where one side is positive and the other is negative

ion-dipole

force between a full ionic charge and a partial charge on a polar molecule

ion-induced dipole

• when an ion is placed next to nonpolar molecule, the ion causes it to be a dipole

• temporary

• induced dipole - induced dipole (London dispersion force)

• dipole - induced dipole (Debye Induction force)

• dipole - dipole (Keesom Orientation force)

  • hydrogen bond

Van der Waals forces (3)

induced dipole - induced dipole (London dispersion force)

• dominant force between nonpolar (uncharged)

• weakest bond

• Cl₂ & Cl₂

0.5-1 kcal/mole

energy of induced dipole - induced dipole (London dispersion force)

dipole - induced dipole (Debye Induction force)

• force between polar (charged) and nonpolar (uncharged)

• H₂O and O₂

1-3kcal/mole

energy of dipole - induced dipole (Debye Induction force)

dipole - dipole (Keesom Orientation force)

• force between 2 polar (charged)

• CO & CO

1-7 kcal/mole

energy of dipole - dipole (Keesom Orientation force)

• stronger

• weaker

for ionic bonds, electrostatic interactions get _____ as the charges increases and ____ as the size of the ions increases

• stronger

• weaker

for ionic bonds:
the higher the charge, the ____ the bond
the bigger the atom, the ____ the bond

higher

the higher the electrostatic interaction, the _____ the boiling point and melting point

c) ionic bond > covalent bond > ion-dipole > H-bond > Keesom > Debye > London

which order is correct? (strongest to weakest)

a) ion-dipole > ionic bond > covalent bond > H-bond > Keesom > London > Debye
b) ionic bond > covalent bond > H-bond > ion-dipole > Debye > Keesom > London

c) ionic bond > covalent bond > ion-dipole > H-bond > Keesom > Debye > London

b) covalent, sharing

oxygen atoms have six valence electrons and hydrogen has 1 valence electron. When their atoms bond, they will form a ____bond by ____ their electrons

a) ionic, sharing

b) covalent, sharing
c) covalent, transferring

d) ionic, transferring

c) S

which one of the following elements is least likely to participate in a hydrogen bond?

a) O

b) N
c) S
d) F

London dispersion force

the weak intermolecular force that results from the motion of electrons that creates temporary dipoles in molecules

oxygen

what element in a water molecule has partial negative charge?

polarity

an uneven distribution of electrons causing charges on each element in the molecule