Physical Chemistry- Bonding

Question 1

Define a metallic bond

Answer 1

Attraction between delocalised outer shell electrons and positive metal ions

Question 2

How are metals arranged?

Answer 2

Regular arrangement
Giant metallic lattice- (giant=endlessly repeating)

Question 3

Define an ionic bond

Answer 3

Strong electrostatic attraction between oppositely charged ions

Question 4

Define a covalent bond

Answer 4

A shared pair of electrons

Question 5

What is a lone pair?

Answer 5

Pair of electrons that are not bonded

Question 6

Define coordinate bonds

Answer 6

A covalent bond in which the shared pair of electrons come from the same atom.
NH3 + H -> NH4

Question 7

How are coordinate bonds represented?

Answer 7

A line with an arrow in the middle

Question 8

What is the electron repulsion theory?

Answer 8

lone pair- lone pair > lone pair- bonded pair > bonded pair-bonded pair

Question 9

How much does the lone pair repel the bond angle?

Answer 9

By 2.5 degrees

Question 10

Define electronegativity

Answer 10

The power of an atom to attract the pair of electrons in a covalent bond

Question 11

What happens to electronegativity as you go across a period?

Answer 11

Increases
Nuclear charge increases

Question 12

What happens to electronegativity as you go down a group?

Answer 12

Decreases
Atomic radius increases
Shielding increases

Question 13

What is the most electronegative element?

Answer 13

Fluorine

Question 14

Define a polar bond

Answer 14

Uneven distribution of electrons

Question 15

Describe a polar bond in terms of electronegativity

Answer 15

Uneven electronegativity so bonded electrons are attracted to the more electronegative element
Dipole has formed

Question 16

Describe an ionic bond in terms of electronegativity

Answer 16

Large difference in electronegativity
Electrons have been pulled so far enough towards the more electronegative atom that they have been lost and have formed ions

Question 17

Electronegativity between C-H

Answer 17

Similar electronegativity so it is non-polar

Question 18

What are the three types of intermolecular forces?

Answer 18

Van der Waals
Permanent dipole-dipole
Hydrogen bonds

Question 19

When do Van der Waals forces act?

Answer 19

Occurs in all substances

Question 20

When do permanent dipole-dipole forces act?

Answer 20

Between molecules with a permanent dipole

Question 21

When do hydrogen forces act?

Answer 21

Between O-H, N-H, F-H

Question 22

How are Van der Waals forces created?

Answer 22

Caused by an instantaneous dipole due to the constant movement of electrons
This induces a dipole in other molecules resulting in a very weak force of attraction

Question 23

How do VdW forces increase?

Answer 23

Bigger molecules have bigger a Mr = more electrons = induced dipole is larger

Question 24

What do hydrogen bonds form between?

Answer 24

Hydrogen and lone pair of electrons on O,N or F

Question 25

Properties of substances with hydrogen bonding

Answer 25

High melting/boiling points due to the strength of hydrogen bonds
Soluble because it forms hydrogen bonds with water