T3 Definitions (kapoor) Flashcards
Adsorption
The process that occurs when a gass liquid or solute is held to the surface of a solid or more rarely a liquid
Boltzmann distribution
The distribution. Of energies of a molecules at a particular temperature, usually shown as a graph
Catalyst
A substance that increases the rate of a chemical reaction. Without being used up in the process
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
Endothermic reaction
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 surrounding
Enthalpy
The heat content that is stored in a chemical system
Standard enthalpy change of combustion
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.
Standard enthalpy change of formation
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.
Standard enthalpy change of reaction
The enthalpy change that accompanies a reaction in the molar quantities expressed in a chemical equation under standard conditions, all reactants and products being in their standard states.
Enthalpy cycle
A diagram showing alternative routes between reactants and products which allows the indirect determination of an enthalpy change from other known enthalpy changes using Hess’ law.
Enthalpy profile diagram
A diagram for the reaction to complacency the enthalpy of the reactants with the enthalpy of yhe products
Hess law
If a reaction can task place by more than one route and the initial and final conditions are the same, the total enthalpy chmage is the same for each route
Heterogeneous catalyst
A reaction in which the catalyst gas a differnt physical state for the reactants, frequently, reactants are gases whilst the catalysts is a solid
Homogenous catalysis
A reaction in which the catalysts and reactants are in the same physical state whichh is most frequently the aqueous or gaseous state
Second ionisation energy
The energy required to remove one electron from each ion in one mole of gaseous 1+ ions to form one mole of gaseous 2+ ions.
Successive ionisatio. Energy
A measure of the energy required to remove each electrons in turn
Kc
equilibrium constant us3d to predict position of equilibrium
Le chateliers principle
When a system in dynamic equilibrium is subjected to a change the position of equilibrium will shift to minimise the change
Periodicity
A regular periodic variation of properties of elements with atomic number and position in the periodic table
Rate of reaction
The change in concentration of a reactant or a product in a given time
Specific heat capacity
The energy required to raise the temperature of 1b of a substance by 1°c
Standard condition s
A pressure of 100kpa, a stated temperature, (298K)
Conc 1 mol dm-3
Acid
A species that is a proton donor
Alkali
A type of base that dissolves in water forming hydroxide ions
Base
Species that is a proton acceptor
Disproportionation
The oxidation and reduction of the same element in a redox reaction
Mole
The amount of any substance containing ad man particles as there are n exactly 12g of carbon12
Oxidising agent
A reagent that oxides another species
Reducing agent
A reagent that reduces another species
Salt
A chemical compound formed form an acid, when a H+ form the acid has been replaced by a metal ion or another positive ions, such as the ammonium ion NH4+
Bond dissociation energy
Enthalpy change when one mole of covalent bonds is broken to give separate atoms with everything in gaseous state
Mean bond enthalpy
Enthalpy change when one mole of bonds is broken, taken as an average from a range of compounds
Enthalpy og atomisation
Enthalpy change that takes place when one mole of gaseous atoms is formed from an element in it’d standard states
Lattice enthalpy of dissociation
Enthalpy chmage when one mole of an ionic lattice is broke down into its gaseous ions
Enthalpy of lattice formation
Enthalpy change when one mole of a Solif ionic compound is formed from its gaseous ions
What is 1st enthalpy of electron affinity
Enthalpy change when the mole of electrons is added to one mole of gaseous ions atoms
What is 2nd enthalpy of electron affinity
Enthalpy change when one ,oñe of electrons Is added to one mole of gasease ions with a 1- change
Standard enthalpy change of solution
Enthalpy change when one more of an ionic compound is in its starndard states completly dissolved in water to form aq ions under standard conditions
Standard enthalpy change of hydration
Enthalpy change when one mole of gaseous ions dissolve in water to from aq ions under standard conditions
