Definitions E Flashcards
E/Z isomerism
A type of stereoisomerism in which different groups attached to a carbon–carbon double bond may be arranged differently in space because the restricted rotation of the double bond
Electronegativity
A measure of the attraction of bonded atoms for a pair of electrons in a covalent bond
Electrophile
An atom or group of atoms that is attracted to an electron rich centre, where it accepts a pair of electrons
Electrophilic addition
An addition reaction in which the first step is attacked by an electrophile on a of a region of high electron density
Elimination reaction
The removal of a molecule from a saturated molecule to make unsaturated molecule
Empirical Formula
A formula that shows the simplest whole number ratio of atoms of each element present in a compound
End point
The point in a titration where the indicator changes colour; the endpoint indicates when the reaction is just complete
Endothermic reaction
A reaction in which the enthalpy of the product is greater than the enthalpy of the reaction, resulting in a heat being taken in from the surroundings (^H is positive)
Enthalpy
The total heat content in a chemical system
Enthalpy Change, ^H
Difference in enthalpy between reactants and products in a reaction
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 of a reaction to compare the enthalpy of the reactants with the enthalpy of the products
Equilibrium Constant, Kc
A measure of the position of equilibrium; the magnitude of an equilibrium constant indicates whether there are more reactants or more products in an equilibrium system
Exothermic reaction
A reaction in which the enthalpy of the products is smaller than the enthalpy of the reactants, resulting in heat loss to the surroundings (^H is negative)
