Bonding & structure questions

Question 1

Describe the motion of the atoms in a crystal of silicon dioxide

Answer 1

the atoms vibrate around in a fixed position

Question 2

in terms of structure and bonding, describe what happens to the atoms in a crystal of silicon dioxide when it melts

Answer 2

the covalent bonds are broken and the atoms are free to move

Question 3

state the type of intermolecular force(s) in BF3

Answer 3

London

Question 4

state the type of intermolecular force(s) in NF3

Answer 4

London, dipole-dipole

Question 5

what type of bond is formed between a molecule of BF3 and NF3

Answer 5

dative covalent bond

Question 6

by referring to the types of intermolecular force involved, explain why energy must be supplied in order to boil liquid hydrogen chloride

Answer 6

energy is needed to overcome the London and Dipole-Dipole forced

Question 7

Explain why the boiling point of hydrogen bromide lies between those of hydrogen chloride and hydrogen iodide

Answer 7

HBr has an intermediate size, as the London forces depend on molecular size

Question 8

Explain why the boiling point of hydrogen fluoride is higher than that of hydrogen chloride

Answer 8

There are hydrogen bonds in HF, so the intermolecular forces are stronger than HCl

Question 9

What is the electronic configuration of aluminium

Answer 9

1s2 2s2 2p6 3s2 3p1

Question 10

what is the electronic configuration of vanadium

Answer 10

1s2 2s2 2p6 3s2 3p6 4s2 3d3

Question 11

describe the bonding present in metals

Answer 11

the attraction between positively charged nuclei and the delocalised electrons in a cloud of electrons

Question 12

explain how the bonding and structure of metals allow it to be electrical conductors

Answer 12

the freely moving electrons can carry a charge

Question 13

explain how the bonding and structure of metals allow it to be malleable

Answer 13

the layers can slide over each other, whilst the attractive forces remain the same throughout the lattice

Question 14

suggest a reason why aluminium is a better conductor of electricity than magnesium

Answer 14

Aluminium has more outer shell electrons,
AL+3 and MG+2

Question 15

state and explain the trend in electronegativity of the elements across Period 3 from sodium to chlorine

Answer 15

there is an increase in electronegativity across a period, as the nuclear charge increases whilst shielding stays the same

Question 16

why does a molecule of CH3Cl have a permanent dipole but CCL4 is not polar

Answer 16

CH3Cl has asymmetry of polar C-Cl bonds

Question 17

use the kinetic theory to describe the changes that take place as calcium oxide is heated from 25°C to a temperature above its melting point

Answer 17

as temperature increases until the vibrations are so violent that the ions break free at the melting point

Question 18

state 2 properties of calcium oxide that depends on its bonding

Answer 18

• has a high melting and boiling point
• is an electrical conductor as a liquid or gas