Chemistry Unit 2 Inorganic

Shape                                             Bond Angle size                                 Examples

Linear                                                    180                                             BeCl2, HCN,CO2

Bent                                                      104.5                                          H2O, NO2, SnCl2 

Trigonal Planar                                        120                                            CO3, SO3, BF3

Pyrimidal                                                107                                            NH3, PH3

Tetrahedral                                              109.5                                         CH4, CCl4

Square Planar                                          90                                             XeF4

Trigonal Bipyrimidal                                  90 + 120                                    PCL5

Octahedral                                               90                                             SF6

Electronegativity - The measure of attraction for a pair of electrons

Identical atoms - electron density evenly distributed

Different atoms - not evenly distributed

Electronegativity gives atoms charges, such as diople charges where charges of equal magnitude and opposite sign are separated by a small distance

Oxidation

• Loss of electrons
• Gain in oxygen
• Loss of Hydrogen
• Increase in oxidation number

Reduction

• Gain in electrons
• Loss of oxygen
• Gain in hydrogen
• Decrease in oxidation number

Rules

• Oxidation number of an uncombined element is 0
• In a polyatomic ion the sum of the oxidation numbers add up to the charge on the ion
• Many elements have oxidation numbers that do not change

OXIDATION NUMBERS

Group 1 Metals = ALWAYS +1

Group 2 Metals = ALWAYS +2

Aluminium = +3

Hydrogen = +1 (Except metal hydride = -1)

Flourine, Chlorine, Bromine and Iodine = -1

Oxygen = -2

Factors that effect rate:

• Surface Area
• Catalyst
• Pressure
• Concentration
• Temperature
• Light (Photochemical reactions)

Collision Theory --> A particle must collide to react, to successfully react they must have the required activation energy. If there is enough energy then bonds will be broken and new ones formed.

Activation Energy --> The energy barrier which must be overcome before a reaction will occur.

Rate of Reaction --> The speed of a reaction

A Chemical Reaction --> When 2 or more particles collide in correct orientation and with sufficient energy to make the collision successful

Uses graph called the Boltzmann Distribution to show the effect of tempertaure, amount of particles and the energy. The graph shows that at Higher temperatures the amount of particles needed is lower and the energy is higher. For Lower temperatures the amount of particles increase with lower energy. 

Temperature

• High temperature favours the side of an endothermic reaction
• Low tempertaure favours the side of an exothermic reaction

Pressure

• High pressure favours the side of the fewest moles
• Low pressure favours the side of the most moles