bonding

Question 1

Graphite

Answer 1

consists of carbon atoms bonded to 3 other carbon atoms in a 2-D lattice. Delocalised valence electrons are between the layers and the forces of attraction between the layers are weak.

Question 2

Diamond

Answer 2

Consists of carbon atoms covalently bonded in 4 other carbon atoms in a tetrahedral 3-D lattice structure. The covalent bonds are strong so atoms cannot be easily removed.

Question 3

Ion

Answer 3

Consists on ions, ionic bonds

Question 4

Metal

Answer 4

cations and electrons, metallic bonds

Question 5

Molecule

Answer 5

atoms, covalent bonds, covalent network solid

Question 6

Metal conduction

Answer 6

3-D lattice of positively charged metal cations, with delocalised valence electrons bonded to all the metal cations. As these electrons move the metal will conduct electricity as solid & molten

Question 7

Requirement for conduction

Answer 7

Free moving charged particles

Question 8

Ion conduction

Answer 8

ionic solid is a 3-D lattice of cations and anions. In solid, charged particles (ions) are in fixed position and as they do not move, the solid cannot conduct electricity. Molten, ions can move and is able to conduct electricity.

Question 9

Melt ice

Answer 9

endothermic to absorb

Question 10

Heat pack heats up

Answer 10

exothermic as heat is released

Question 11

Shape

Answer 11

_ regions of electron density around the central _ atom. These regions are arranged as far apart as possible to minimise repulsion. They take a _ arrangement with a bond angle of _.

Question 12

All Bonding regions

Answer 12

all regions are bonding therefore the shape is _

Question 13

Not all bonding regions

Answer 13

_ regions are bonded and _ non-bonding lone pair of electrons, therefore the observed shape is _

Question 14

Polarity factors

Answer 14

presence of polar bonds (due to electronegativity differences of the atoms in a bond)
distribution of polar bonds around a central atom
symmetrical/asymmetrical to cancel dipole

Question 15

Polarity

Answer 15

bonded atoms are different and have different electronegativity so there is a bond dipole and the bonds are polar. If symmetrical, the dipole cancels and is non-polar.

Question 16

metal description

Answer 16

_ is a metallic solid made up of atoms that take a regular 3-D arrangement. The valence electrons of the atoms are delocalised, resulting in a regular array of cations held in place by the strong attractions between cations and valence electrons (metallic bond)

Question 17

metal conductivity

Answer 17

_ can conduct electricity as the valence electrons are able to move.

Question 18

metal ductility

Answer 18

the metal is able to be stretched into a wire as when it is hammered, the layers of cations are able to slide over each other without disrupting the strong bonding, this is because metallic bonds are multi directional

Question 19

molecule in high temp

Answer 19

_ has a molecular structure made up of _ molecules held together by weak intermolecular forces of attraction. These forces are easily broken with a small amount of energy.

Question 20

graphite in high temp

Answer 20

graphite is a strong covalent network made up of a regular 2-D arrangement of carbon atoms covalently bonded to each other. A large amount of energy is required to break all the strong covalent bonds.

Question 21

Solubility

Answer 21

for a solute to dissolve in a solvent, the new attractions formed between the solute and solvent molecules must be strong enough to release sufficient energy to overcome the bonds between molecules in the solute and between the molecules in the solvent.

Question 22

non polar solubility in water

Answer 22

water is polar, so there are only weak forces of attraction between water and _. The energy released when these attractions form is not sufficient to overcome the polar water molecules and allow them to separator. _ will not dissolve

Question 23

polar solubility in water

Answer 23

the + and - molecules are strongly attracted to polar water molecules. + is attracted to slightly negative O- atoms. - is attracted to slightly positive H+ atoms. Forming these attractions releases sufficient energy to overcome the attractive forces between water molecules in solvent and in the solute. the molecule will dissolve.

Question 24

force on metal

Answer 24

Metallic solid in 3-D lattice of cations surrounded by free moving electrons. Delocalised electrons hold structure together, as they are attracted to the cations/atoms in the lattice. As force is applied, layers of ions move but do not seperate as the bonding between electrons and ions in non-directional and not disrupted by rearrangement. (is malleable)

Question 25

force on ion

Answer 25

3-D arrangement of alternating + and - ions. When force is applied, layers of lattice slide over each other, causing + ions to align with + ions and - ions to align with - ions. This introduces repulsive forces to lattice and bonding is disrupted as the lattice breaks apart (shatters)

Question 26

non-polar / non-polar solubility

Answer 26

both are non-polar, so attractions are strong enough to overcome existing attractions/bonds, allowing it to dissolve

Question 27

molecule vs covalent network melting/subliming

Answer 27

difference in attractive forces leads to difference in energy needed to break these bonds