Properties of Ionic compound, molecules, metals and alloys Flashcards
structural properties of ionic compounds:
- giant ionic crystal lattice structure
- large number of alternating +,- ions
held tgt by EFA
MP, BP of ionic compounds
- mutual EFA between opp charged ions are strong
- large amt of energy needed to overcome forces
- tend to have very high MP and BP
solid at room temp
hardness of ionic compounds
- strong forces of attraction between opp charged ions are make them resistant to deforming
- tend to be hard as the attractive forces case the ions to resist motion
- when enough force applied, ions move away from lattice postions and ions of same charhe approach each other.
- repulsive force between ions is now larger then attractive forces, lattice structure shatters
- hard but brittle
Solubility of ionic compounds
- soluble in H2O
- insoluble in organic solvents (e.g. alcohol)
- When ionic compounds dissolve in water we say that they are in aqueous state
electrical conductivity of ionic compounds
SOLID STATE:
ions in the lattice vibrate about in their fixed positions and are thus not mobile. cant CE
MOLTEN STATE:
- liquid state.
in molten state or aqueous state the ions are mobile and can CE
structural properties of SIMPLE covalent bonds
molecules are held together by strong covalent bonds.
BUT sre held together by weak intermolecular forces of attraction (IMFOA)
at low temp they can form lattices
MP and BP of SIMPLE covalent bonds
weak IMFOA between molecules are easily overcome by small amt of energy. low MP and BP.
some of them evaporate easily and are known as volatile. exist mostly as G or L state in room temp.
AS MOLECULES GET LARGER IMFOA GETS STRONGER AND MP AND BP IS HIGHER.
Solubility of of SIMPLE covalent bonds
insulble in water, soluble in organic solvents
EC of SIMPLE covalent bonds
- typically exist as neutral molecules , dont have mobile charge carriers to CE.
some simple covalent substances dissosciate in water and can CE
General info of GIANT covalent bonds
- almost always in S state
- strong covalent bonds and IMFOA
Examples of GIANT covalent bonds
Diamond and graphite
allotropes of carbon
the diff bonding and structure of carbon allotropes affect their properties
Allotropes def
Different frosm of the same elemnt with diff structural arrangement of atoms
strutural prop of GIANT covalent bonds
+ graphite exception
- numerous bonds holding many atoms tgt
- very rigid and able to withstand large forces
- graphite however,is diff coz of its layered structure. strong covalent bonds are found within the layers
- but weak IMFOA exist between the layers. this means graphit can easily be seprated from each other but is hard to break
MP BP of GIANT covalent bonds
- very resistant to heat due to large no. of bonds.
- to melt giant covalent substances. large amt of energy is needed to break strong CB.
- solid at room temp
- very high MP BP
Hardness of GIANT covalent bonds
DIAMOND:
hard. made up of only strong CB. a large amt of energy is needed to break the structure apart.
GRAPHITE:
soft and slippery. small amt of energy needed to over weak IMFOA between layers of carbon. layers of carbon atom can slide over each other easily.
Solubility of GIANT covalent bonds
insoluble in water and organic solvents
EC of GIANT covalent bonds
giant covalent structures with no mobile elctrons: Diamond and silicon dioxide doesnt CE
GRAPHITE:
each C atom is bonded to 3 other C atoms, 1 unbonded electron per C atom which is free and mobile to CE
Diaomond, Graphite, Silicon Dioxide.
Which 2 have same properties?
Diamond, SD
Graphite properties
molecular structure
hardness
MP BP
solubility
EC
2d layers (strong CB between C atoms. weak IMFOA between layers of C atom)
soft and slippery
high
insoluble in both
CE along layers
Diamond and SD properties
molecular structure
hardness
MP BP
solubility
EC
3d networks
very hard throughout
hugh
insoluble in both
insulator
Macromolecules and polymers
Polymers are macromolecules. a polymer consists of many covalent molecules joined tgt to form into chains of much larger molecules
Structural properties of polymers
vary greatly in their hardness and flexibility as they exist in many arom combos.
MP BP of polymers
large size - mostly solid at room temp
as polymers may be formed by molecules of a range of sizes. they dont have a fixed MP and BP.
typically soften over a range when the weak IMFOA are overcome by the molecular vibration with higher KE
solubility of polymers
most macromolecules are insulble in water but soluble in organic solvents.
EC of polymers
not able to CE as they dont have any mobile electrones in any state.
what is a metallic bond exactly?
the mutual EFA between positively charged metal ions and the SODE
structure of metals and alloys
- giant metallic latice
- atoms occupy fixed positions
- evenly distributed throughout the solid
- metals in solid state have strong metallic bond
What is an alloy?
mixture of a metal with 1 or more otther elements.
diff between pure metals and alloys
the irregular lattice arrangements in alloys. it leads to the diff in prop. between allouys and pure metals
Structural prop. of metals
- have a regular structure
- enough force is applied, layers of atoms can slide over one another easily
- can be flattened into thin sheets (malleable)
- can be pulled without breaking (ductile)
THE SODE WILL CONTINUE TO HOLD THE METAL IONS TGT UNLESS A MUCH GREATER FORCE IS APPLIED
Structural prop. of alloys
- in alloys, the atoms are of diff sizes.
- larger force is needed to make the layers slide over each other
- alloys are less malleable and less ductile
- harder and stronger
MP BP of metals and alloys
metals:
- high MP BP coz atoms are held tgt in a lattice by strong metallic bond
alloys:
- alloys are mixtures
- melt over a range
good conducter of heat as delocalised valence electrons allow effient transfer of thermla energy throughout the giant metallic structure
Ec of metals and alloys
the SODE found in both makes them good EC
