structure and properties of materials

Question 1

structural properties of ionic substances

Answer 1

giant ionic lattice structure with a large number of alternating positive and negative ions held together by electrostatic forces of attraction

Question 2

Hardness of ionic substances

Answer 2

strong forces of attraction between the oppositely charges ions makes ionic compounds resistance to deforming, they are hard but brittle

Question 2

Melting point and boiling point of ionic substances

Answer 2

a large amount of energy is needed t overcome the strong electrostatic forces of attraction, causing a very high melting point and boiling point

Question 3

solubility of ionic substances

Answer 3

soluble in water and insoluble in organic solvents

Question 4

electrical conductivity of ionic substances

Answer 4

when an ionic compound is in the solid state, the ions in the lattice are only able to vibrate about their fixed positions. there are no mobile charge carriers and hence, no electrical conductivity

when an ionic compound is i the aqueous state or molten state, there are mobile charge carriers to conduct electricity and there is electrical conductivity

Question 5

solubility of simple covalent substances in water

Answer 5

generally insoluble

Question 6

structure of simple covalent substances

Answer 6

simple covalent structure. small discrete molecules

Question 7

bonding between simple covalent structures

Answer 7

weak intermolecular forces of attraction

Question 8

Melting point and boiling point of simple covalent structures

Answer 8

small amount of energy needed to overcome the weak intermolecular forces of attraction. low melting point and boiling point

Question 9

electrical conductivity of simple covalent structures

Answer 9

consist of electrically neutral molecules with no free electrons or ions. most does not conduct electricity in all states. (except hydrogen chloride with dissolve in water to form mobile ions that can carry charges)

Question 10

hardness of simple covalent molecules

Answer 10

soft due to the weak intermolecular forces of attraction

Question 10

structure of giant covalent molecules

Answer 10

giant covalent structure with atoms bonded by covalent bonding

Question 11

bonding between giant covalent structures

Answer 11

strong covalent bonds between atoms throughout

Question 12

melting and boiling points in giant covalent structures

Answer 12

very high melting and boiling points as a very high amount of energy is needed to overcome the strong covalent bonds within the atoms

Question 13

solubility in water for giant covalent substances

Answer 13

insoluble

Question 14

electrical conductivity in giant covalent structures

Answer 14

does not conduct electricity (except graphite)

each carbon atom in graphite is bonded with three other carbon atoms. the carbon atoms have 1 valence electron that becomes delocalised as it is not used for bonding. there are then delocalised electrons that are mobile and can carry charges within the layers

Question 15

hardness of giant covalent structures

Answer 15

hard

exception : graphite which has weak intermolecular forces within the layers

Question 15

structure of macromolecular substances

Answer 15

large polymer-like molecules, small molecules joined together by covalent bonds

Question 16

bonding between macromolecular structures

Answer 16

strong covalent bonds in a chain or network

Question 17

mpt and bpt of macromolecular structures

Answer 17

varies depending on molecular weight and structure

typically low mpt and bpt as a small amount of energy is needed to overcome the weak intermolecular forces of attraction between the long chain molecules in the polymer

Question 18

solubility in water for macromolecular structures

Answer 18

insoluble

Question 18

electrical conductivity in macromolecular structure

Answer 18

generally does not conduct electricity

Question 19

hardness in macromolecular structures

Answer 19

varies (some are soft, some are hard)

Question 20

structure of metallic substances

Answer 20

giant metallic lattice structure. lattice of positive metal ions in a sea of delocalised mobile electrons

Question 21

mpt and bpt of metallic structures

Answer 21

high mpt and bpt as a large amount of energy is needed to overcome the strong electrostatic forces of attraction between the positively charged ions and the sear of delocalised mobile electrons

Question 22

solubility in water for metallic substances

Answer 22

insoluble

Question 22

electrical conductivity for metallic substances

Answer 22

conducts in solid and molten states due to the sea of delocalised and mobile electrons

Question 23

hardness of metallic substances

Answer 23

malleable and ductile as the layers of atoms slide over one another