Chemistry 3

Front 1

Enthalpy

Back 1

the heat content that is stored ina chemical system

Front 2

Exothermic

Back 2

a reaction in which the enthalpy of the products is smaller than that of the reactants, resulting in heat loss to the surroundings.

Front 3

Endothermic

Back 3

a reaction in which the enthalpy of the products is grater than that of the reactants, resulting in heat being taken in from the surroundings.

Front 4

Activation Energy

Back 4

the minimum energy required to start a reaction by the breaking of bonds.

Front 5

Standard Conditions

Back 5

Pressure- 101 kPa
Temperature- 25 degrees celsius
Concentration- 1.0 mol dm -3

Front 6

Standard enthalpy change of reaction

Back 6

the enthalpy change that accompanies a reaction in the molar quantities expressed in a chemical equation under standard conditions, all reactant and products being in their standard states.

Front 7

Standard enthaply change of combustion

Back 7

the enthalpy change that takes place when one mole of a substance reacts completely with oxygen under standard conditions, all reactants and products being in their standard states.

Front 8

Standard enthalpy change of formation

Back 8

the enthalpy change that takes place when one mole of a compound is formed from its constituent elements in their standard states under standard conditions.

Front 9

Specific heat capacity

Back 9

the energy required to raise the temperature of 1g of a substance by 1 degree celsius.

Front 10

Bond Enthalpy

Back 10

the enthalpy change that takes place when breaking by homolytic fission, 1 mole of a given bond in the molecules of a gaseous species.

Front 11

Average bond enthalpy

Back 11

the average enthalpy change that takes place when breaking by homolytic fisson, 1 mole of a given bond on the molecules of a gaseous species.

Front 12

Hess' Law

Back 12

If a reaction can take place by more than one route and the initial and final conditions are the same, the total enthalpy change is the same for each route.

Front 13

Rate of reaction

Back 13

the change in concentration of a reactant or a product in a given time.

Front 14

Boltzmann Distribution

Back 14

the distribution of energies of molecules at a particular temperature, often shown as a graph.

Front 15

le Chatelier's principle

Back 15

states that when a system in dynamic equilibrium is subjected to a change, the position of equilibrium will shift to minimise the change.

Front 16

Dynamic Equilibrium

Back 16

the equilibrium that exists in a closed system when the rate of the forward reaction is equal to the rate of the reverse reaction.