-
Metallic bonds are characterised as
metal + metaldelocalised sea valence elections around metal ions
-
Ionic bonds are characterised as
metal + non metal Metal Cation (+) + Non Metal Anion (-) eg NaClLow Ionisation Energy + High Electron AffinityElectrostatic attraction between + and -
-
Covalent Bonds are characterised as
non metal + non metal Sharing an electron pair between atoms so result is more stable than constituentseg. Cl2
-
Network Covalent compounds are characterised as
Strong covalent bonding throughoutNO molecules3D array in latticeHard, insolubleInsulator or ConductorHigh melting and boiling points
-
The properties of Covalent compounds are
Strong Intramolecular bondingWeak Intermolecular bonding (except network covalent structures)Gas, liquid or solidPoor conductorslow melting and boiling point
-
The properties of Metal are
solid or liquidmalleable and ductileelectrical and thermal conductorsmoderate melting pointmoderately high boiling point
-
The properties of Ionic Compounds are
solidrigid and brittlehigh melting pointhigh boiling pointpoor conductors
-
What shape do 2 domains give?
Linear
-
What shape do 3 domains give?
Trigonal Planar
-
What shape do 4 domains give?
Tetrahedral
-
What shape do 5 domains give?
Trigonal Bipyramidal
-
What shape do 6 domains give?
Octahedral
-
When dissolving molecules in water, what is important?
Ability to participate in H bonding, eg (Acetic Acid) -COOH readily participates due to lone pair on OH attracting positive H
-
The two major divisions of polymer are
1. Biopolymers (carbohydrates, proteins etc)2. Synthetic polymers (rubber, nylon etc)
-
The 2 main synthetic routes of polymers are
1. Addition Polymers (polyethylene)2. Condensation Polymers (nylon)
-
Proteins are
Polypeptides
-
The processes of radioactive decay are
- 1. alpha decay -> -4/2 He Particle2.
- Beta decay -> - 0/-1 e + 1/1 p3.
- Gamma decay -> gamma photon
-
Using Half life in kinetics is given by
- t1/2 = 0.693/k
- solve for k k = decay constant[
- A]o = concentration at initial
- [A]t = concentration at time
- rearrange equation time = (ln initial - ln final) /k
-
The class of an electrolyte is determined by what?
The conductivity of a solute
-
What are the characteristics of a weak electrolyte?
- Covalent compounds
- partially dissociate into ions
- Conduct electricity poorly
- eg. H2O
-
What are the characteristics of a non electrolyte?
- Do not dissociate at all
- Do not conduct at all
- eg. sucrose stays as sucrose in water
-
What are the characteristics of a strong electrolyte?
Ionic compounds which completely dissociate into ionsconduct electricity well
-
What is the relationship between water molecules and cations?
It goes down as you go down a group. The cations with a higher charge density attract more water molecules. This is the reverse of the trend of atomic radii. Hydrated ions are more mobile and thus can transfer charges quickly.
-
What is a Hydrogen Bond?
A weak attractive force between a hydrogen atom and the lone pair of electrons on atoms such as oxygen, nitrogen and fluorine
-
What are the two types of Hydrogen Bonding?
- Intermolecular - between 2 molecules eg H2O and H2O
- Intramolecular- between 2 parts of the same molecule eg. DNA structure
-
What conditions must exist for a Hydrogen bond to exist?
- Donor atom - electron withdrawing group (NOF) taking charge from the hydrogen
- Acceptor atom - must have available lone pair (NOF)
-
What 3 factors influence Hydrogen Bond Strength?
- 1. Electronegativities of donor and acceptor - more electronegativity from donor and more eletrons from acceptor
- 2. Hydrogen and Acceptor bond length
- 3. Bond angle should be close to 180 degrees as possible
-
What is evidence for Hydrogen bonding?
mp, bp are increased due to H bonding
-
What is the difference between First Order Reactions and Second Order Reactions?
- First Order = -k
- Second Order = +k
-
-
-
-
-
-
-
-
-
-
|
|