Definitions 2 Flashcards
Functional group
An atom or a group of atoms that form the centre of chemical activity in the molecule.
Structural isomers
Compounds having the same molecular formula but different structural formula
Heat of reaction
The net change of chemical potential energy of the system.
Exothermic reaction
Reactions which transform chemical potential energy into thermal energy
Endothermic reactions
Reactions which transform thermal energy into chemical potetial energy
Activation energy
The energy required to form the activated complex
Activated complex
A high energy, unstable, temporary transition state between the reactants and the products
Reaction rate
The change in concentration per unit time of either a reactant or product.
Catalyst
A substance that increases the rate of the reaction but remains unchanged at the end of the reaction
Closed system
A system in which mass is conserved inside the system but energy can enter or leave the system freely
Open system
A system in which both energy and matter can be exchanged between the system and its surroundings
Le chateliers principle
When an external stress is applied to a system in dynamic chemical equilibrium, the equilibrium point will change in such a way as to counteract the stress.
Lowry-Bronsted theory
An acid is defined as a proton donor. A base is defined as a proton acceptor.
Ionisation
The reaction of a molecular substance with water to produce ions.
Strong acid
An acid that ionises completely in an aqueous solution.
