Definitions of AS Chemistry unit 2

HideShow resource information
Enthalpy Change
The change in heat energy under constant pressure
1 of 33
Standard conditions
100kPa and 298K
2 of 33
Exothermic reactions
Heat is given out by particles (Exo = Extra)
3 of 33
Endothemic reactions
Heat is taken in by the particles (Endo = End of heat)
4 of 33
Standard Enthalpy of Formation
The standard enthalpy change when one mole of a compound is formed from its elements under standard condidtions
5 of 33
Standard Enthalpy of Combustion
The standard enthalpy when on emole of a compound is burned completely in oxygen under standard condidtions
6 of 33
Activation energy
The minimum amount of energy needed for collisions to be succesful
7 of 33
Collision Frequency
Number of collisions between particles per second
8 of 33
Collision Energy
Combined kinetic energy of colliding particles
9 of 33
Rate of Reaction
Change in concentration per unit of time
10 of 33
Catalyst
A substance that increases the rate of reaction without chemically being changed itself
11 of 33
Dynamic Equalibrium
A reaction where both the forward and backward reactions occur at the same rate, with the same concentration of products and reactants
12 of 33
Le Chateliers principle
When a reaction at equilibrium is changes, the system changes in order to counter-balance this change and regain equalibrium
13 of 33
Oxidation
Loss of electrons
14 of 33
Reduction
Gain of electrons
15 of 33
Oxidizing agent
Electron acceptor
16 of 33
Reducing agent
Electron donor
17 of 33
Oxidation number
charge that would occur on an atom if the bonding were completely ionic
18 of 33
Redox reaction
Electrons are transferred from on species to another
19 of 33
Geometrical isomerism
The same molecular formula but different structural arrangement around a double bond
20 of 33
Addition
Combination of 2 or more molecules to for a single molecule
21 of 33
Substitution
Replacement of one atom/group of atoms by another
22 of 33
Elimination
Loss of a small molecule from a larger molecule to form an unsaturated compound
23 of 33
Electriphile
Species which can accept an electron pair from a different species
24 of 33
Nucleophile
Species wich can use a lone pair of electrons to form its covalent bond in substitution or elimination
25 of 33
Free Radical
Species with a free unpaired electron
26 of 33
Homolytic Fission
Breaking of a covalent bond in a way that one electron goes to each atom
27 of 33
Heterolytic Fission
Breaking of a covalent bond in a way that both electrons go to the sae atom
28 of 33
Hydration
Addition of water
29 of 33
Hydrolysis
Addition of water to break a covalent bond
30 of 33
Oxidation
Addition of oxygen or removal of hydrogen
31 of 33
Polymerisation
Combination of a large number of monomers to form a single chain
32 of 33
Biofuel
A fuel produced from a renewable source
33 of 33

Other cards in this set

Card 2

Front

100kPa and 298K

Back

Standard conditions

Card 3

Front

Heat is given out by particles (Exo = Extra)

Back

Preview of the back of card 3

Card 4

Front

Heat is taken in by the particles (Endo = End of heat)

Back

Preview of the back of card 4

Card 5

Front

The standard enthalpy change when one mole of a compound is formed from its elements under standard condidtions

Back

Preview of the back of card 5
View more cards

Comments

No comments have yet been made

Similar Chemistry resources:

See all Chemistry resources »See all Key words resources »