OG unit 1.5 Flashcards
How are the crystal coordination numbers defined?
Number of nearest ions to each other ions + vice versa
How to say the crystal structure for sodium chloride?
6 ions around each other ion therefore it has a 6.6 coordination
What’s the name for sodium chloride’s crystal structure?
[interlocking?] face? centre cubic
Why is caesium chloride’s structure called body-centred cubic? (bcc)
Well in the cube, there’s one singular caesium ion and each corner of the cube consists of chloride
What does sodium chloride + caesium chloride have in common?
(structure and bonding)
It’s said to be giant and the bonding is ionic
What’s the melting point for strong ionic bonds?
Lot’s of heat req. = very high mp
Strong force of attraction between oppositely charged ions
What’s the conductivity for strong ionic bonds?
Zero as the solid ions fixed in a lattice.
However they can conduct if molten/dissolved in water as ions free to move + carry current
What’s the hardness for strong ionic bonds?
Hard but brittle. Can be cleaved easily (breaks crystal lattices)
Define allotrope
Different forms of the same chemical element
Properties of Graphite?
(6 things)
- High m.p, lots of heat req to break covalent bonds
- 4 valence (outer most shell) what da frick does that mean
- 3/4 e- used in bonding
- 1 free e- to move (delocalised) + carry electrical current
- Hexagonal layers of carbons connected to 3 other carbons by strong covalent bonds
- Layers held together by weak intermolecular forces that can easily be overcome = layers slide off easily past each other
Use of Graphite and why?
Lubricants and pencils
Cuz it’s slippery and soft
1 thing in common of diamond and graphite?
Very high mp due to very strong covalent bonds
What structure and bonding of diamond + graphite?
The structures are said to be giant and the bonding is covalent
Properties of Diamond?
(Only 3 things)
Technically similar to graphite but wayy stronger because:
- Each carbon atom bonded to 4 others, forming 3-dimensional structure (a tetrahedral structure)
- Has stronger intramolecular bonds = more energy req to overcome bonds
- 0 electrical conductivity compared to graphite cuz no free e- to carry the current
Use of diamond and why?
Drill bit cuz like
it’s rlly strong
wat 3 other forms of carbon?
- Buckminsterfullerene
- Graphene
- Carbon nanotubes
This may be needed im not sure but if it is in there, just know u have failed miserably
What happens when iodine is heated?
Turns into gas
(was this rlly needed? welp the more u know)
What type of structure is iodine? and why it got strange property of it to turn into gas or something like that?
- Face-centred cubic
- Has weak VDW forces
Explain ice’s structure or summin like that
(3 things)
- Hydrogen bonds between water molecules hold them together
- In a fairly open tetrahedral structure
- Strong bonds within the water molecules are polar covalent
What’s the ‘electron sea’ model for bonding in metals?
That lattice drawing thingy majiggy:
- Neat rows of positive metal ions
- Electrons free to move (delocalised) and carry on electric current
What structure and bonding of them metals?
Giant, metallic
How can metals differ?
Different number of ion charges = different number of delocalised electrons
How do metals conduct electricity?
- Plenty of delocalised electrons
- Free to move and carry current
How does metal have high melting & boiling points?
- Strong electrostatic attraction
- Between oppositely charged particles
(ion + electron = metallic bonds)
^ idk, this was in the book
Define malleable?
Easily shaped
Define ductile?
Easily stretched into wires or summin?
How can metals exhibit malleable/ductile properties?
- Arranged in neat rows (bonding)
- Can easily slide past each other
Properties of giant ionic compounds (such as the chlorides)?
Just do last 4
Generally:
- Hard
- Brittle
- High mp due to strong ionic bonds
- No electrical conductivity in solid state, ions fixed in position
- Conducts when molten/aqueous solutions (ions free to move and carry electric current)
- Can sometimes not be solube in water depending on energetics/chemical reaction factors, but most ionic chlorides are soluble
2 giant covalent compounds?
and 1 new info
Diamond and graphite
- Insoluble in water
Info of simple covalent compounds? (iodine)
- Doesn’t conduct electricity (no free electrons)
- Soft and volatile (easily evaporated) due to iodine molecules held together by weak Van de Waal’s forces
Additional info of metallic bonding?
(only do last 2)
Delocalised electrons:
- Allow to conduct an electrical current
- Allows good thermal conductivity
- Melting temp & hardness increases
- With number of electrons per atom involved with bonding
Lastly, it’s all about gathering questions to respond to
Alright
