Chemical Bonding - Intramolecular Bonds

Question 1

Intramolecular Bond

Answer 1

Occurring between atoms within molecules

Question 2

Electronegativity

Answer 2

A measure of the tendency of an atom to attract a bonding pair of electrons

Question 3

Covalent Bonds

Answer 3

A sharing of at least one pair of electrons by two atoms

Question 4

Non-polar covalent bonds

Answer 4

An equal sharing of electrons

Question 5

Polar covalent bond

Answer 5

An unequal sharing of electrons leading to a dipole forming (as a result of electronegativity difference)

Question 6

Ionic Bonds

Answer 6

A transfer of electrons and subsequent electrostatic attraction

Question 7

Metallic Bonds

Answer 7

A bond between a positive kernel and a sea of delocalised electrons

Question 8

Why are the melting and boiling points high of diamond, graphite and silicon dioxide?

Answer 8

This happens due to strong covalent networks being broken

Question 9

What determines the melting and boiling points of ionic substances

Answer 9

In giant ionic solids (sodium chloride) the melting and boiling points are determined by the electrostatic forces of attraction (ionic bonds) between the cations (+) and anions (-) in the lattice structure

Question 10

Why must there be forces between molecules?

Answer 10

Because in a liquid or a solid there must be forces between the molecules causing them to be attracted to one another, otherwise the molecules would drift apart and become a gas

Question 11

Intermolecular forces

Answer 11

A weak force of attraction between molecules or between atoms of noble gases

Question 12

Dipole-Dipole

Answer 12

• Attraction between polar molecules (permanent dipoles) of the same substance or different substances.
• Oppositely charged sides of polar molecules align towards each other
• Electrostatic force of attraction is produced between the dipoles

Question 13

Ion-dipole

Answer 13

• Attraction between an ion and a polar molecule containing a dipole.
• The ion aligns itself to the oppositely charged side of the dipole

Question 14

Induced Dipole (London Dispersion Forces)

Answer 14

• Attraction between non-polar molecules or atoms
• the continuous motion of electrons surrounding an atom or molecule may cause an uneven electron distribution of electrons so that one side of the atom contains more electrons that the other, producing a dipole.
• This motion induces another dipole through a chain reaction

Question 15

Hydrogen Bonding

Answer 15

• a special case of dipole-dipole bonding force between polar molecules containing an H atom bonded to an N,O or F atom
• N, O and F form a very strong dipole with an H atom

Question 16

What affects the melting point and boiling points within simple molecular substances?

Answer 16

The strength (influencec by the number of electrons and the polarity of the molecule) and the relative number of intermolecular forces

Question 17

Why are hydrogen bonds so strong?

Answer 17

They are very small and can move very close together.