Bonding

Question 1

What is ionic bonding and give an example

Answer 1

Strong electrostatic forces between oppositely charged ions in a lattice
E.g NaCl (salt)

Question 2

Describe and explain why ionic bonding has its properties?

Answer 2

High m.p. and b.p. —> requires lots of energy to break electrostatic forces
Conducts electricity —> when in solution ions are free to carry charge

Question 3

What is simple molecular covalent bonding?
Give some of its properties

Answer 3

Strong covalent bonds between atoms but weak Van der Waals
Cannot conduct electricity (electrons aren’t free to move)
Has a low m.p. and b.p. (weak VdW)

Question 4

Describe macromolecular bonding and give some of its properties

Answer 4

Lattice of many atoms held together by covalent bonds
High m.p. and b.p.
Doesn’t conduct electricity

Question 5

Compare and contrast the structure of diamond and graphite

Answer 5

Both have a macromolecular covalent structure
Each C in diamond is bonded to 4 others
In graphite each C is only bonded to 3

Question 6

Describe metallic bonding

Answer 6

Lattice of +ve metal ions strongly attracted to a sea of delocalised electrons

Question 7

Explain the trends and properties of metallic bonding

Answer 7

High m.p. and b.p. —> strong attraction betwenn +ve ions and -ve electrons
Conduct electricity —> delocalised electrons can carry charge
Strength of bond increases across the period —> more delocalised electrons which means a stronger force between them

Question 8

Define electronegativity (EN)

Answer 8

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

Question 9

What affects EN?

Answer 9

Nuclear charge
Atomic radius
Electron shielding

Question 10

What’s the difference between a non-polar and polar bond?

Answer 10

Non-polar = both bonding atoms have the same EN
Polar = bonding atoms have different EN

Question 11

Describe Van der Waals force of interaction

Answer 11

Random movement of electrons creates temporary dipoles
Induces dipole in neighbouring molecule
Temporary induced dipole-dipole (VdW)

Question 12

Describe a permanent dipole-dipole attraction

Answer 12

Molecules with polar bonds have permanent dipoles
Attraction between those dipoles and neighbouring molecules

Question 13

What is a dative/co-ordinate covalent bond?

Answer 13

When an electro deficient atom accepts a lone pair of electrons from another atom

Question 14

Name the shape, bond angle and how many bonded and lone pairs there are

Answer 14

Linear = 180 —> 2b, 0l
Trigonal Planar = 120 —> 3b, 0l
Tetrahedral = 109.5 —> 4b, 0l
Trigonal bypyramid = 90 and 120 —> 5b, 0l
Octahedral = 90 —> 6b, 0l