The heat content that is stored in a chemical system
1 of 20
Exothermic
A reaction in which the enthalpy of the products is smaller than the enthalpy of the reactants, resulting in heat loss to the surroundings
2 of 20
Endothermic
A reaction in which the enthalpy of the products is greater than the enthalpy of the reactants resulting in heat being taken in from the surroundings
3 of 20
Enthalpy Profile Diagram
A diagram for a reaction to compare the enthalpy of the reactants and the products
4 of 20
Activation Energy
The minimum energy required to start a reaction by the breaking of bonds
5 of 20
Standard Conditions
A pressure of 100 kPa (1 atmosphere), a stated temperature usually 298K and a concentration of 1 mol dm-3 for reactions with aqueous solutions
6 of 20
Standard State
The physical state of a substance under the standard conditions of 100 kPa and 298K
7 of 20
Standard Enthalpy Change of REACTION
The enthalpy change that accompanies a reaction in the molar quantities expressed in a chemical equation under standard conditions and all reactants and products in their standard states
8 of 20
Standard Enthalpy Change of COMBUSTION
The enthalpy change that takes place when one mole of a substance completely reacts with oxygen under standard conditions, all reactants and products in their standard states
9 of 20
Standard Enthalpy Change of FORMATION of a compound
The enthalpy change that takes place when one mole of a compound is formed from its constituent elements in their standard states and under standard conditions
10 of 20
Specific Heat Capacity
The energy required to raise the temperature of 1g of a substance by 1 C
11 of 20
Bond Enthalpy
The enthalpy change that takes place when breaking by homolytic fission 1 mol of a given bond in the molecules of a gaseous species
12 of 20
Average Bond Enthalpy
The average ethalpy change that takes place when breaking by homolytic fission 1 mol of a given type of bond in the molecules of a gaseous species
13 of 20
Hess' Law
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
14 of 20
Enthalpy Cycle
A diagram showing alternative routes between reactants and products which allows the indirect determination of an ethalpy change from other known ethalpy changes using Hess' law
15 of 20
Heterogeneous Catalysis
Catalysis of a reaction in which the catalyst has a different physical state from the reactants; frequently, reactants are gases whilst the catalyst is a solid
16 of 20
Homogeneous Catalysis
Catalysis of a reaction in which the catalyst and reactants are in the same physical state, which most frequently the aqueous or gaseous state
17 of 20
Boltzmann Distribution
The distribution of energies of molecules at a particular temperature, often shown as a graph
18 of 20
le Chatelier's principle
States that when a system in dymanic equilibrium is subjected to a change, the position of equilibrium will shift to minimise the change
19 of 20
Dynamic Equilibrium
The equilibrium that exists in a closed system when the rate of the forward reaction is equal to the rate of the reverse reaction
20 of 20
Other cards in this set
Card 2
Front
A reaction in which the enthalpy of the products is smaller than the enthalpy of the reactants, resulting in heat loss to the surroundings
Back
Exothermic
Card 3
Front
A reaction in which the enthalpy of the products is greater than the enthalpy of the reactants resulting in heat being taken in from the surroundings
Back
Card 4
Front
A diagram for a reaction to compare the enthalpy of the reactants and the products
Back
Card 5
Front
The minimum energy required to start a reaction by the breaking of bonds
Comments
No comments have yet been made