Unit 2 Definitions Flashcards
(25 cards)
Define: General formula
The simplest algebraic formula for a member of a homologous series
Define: Structural formula
The minimal detail that shows the arrangement of atoms in a molecule
Define: Skeletal formula
The simplified organic formula shown by removing hydrogen atoms from alkyl chains leaving just a carbon skeleton and functional groups
Define: Homologous series
A series of organic compounds having the same functional group, but with each successive member differing by CH2
Define: Functional group
The group of atoms responsible for the characteristic reactions of a compound
Define: Structural isomers
Compounds with the same molecular formula, but different structural formulae
Define: Stereoisomers
Compounds with the sane structural formula, but with a different arrangement in space
Define: E/Z isomerism
An example of stereoisomerism, in terms of restricted rotation about a double bond and the requirement for two different groups to be attached to each carbon atom of the C=C group
Define: Cis-Trans isomerism
A special case of E/Z isomerism in which two of the substituent groups are the same
Define: Homolytic fission
Forming two radicals
Define: Heterolytic fission
Forming a action and an anion
Define: Radical
A species with an unpaired electron
Define: Electrophile
An electron pair acceptor
Define: Nucleophile
An electron pair donar
Define: Standard conditions
100 kPa (1 atmosphere), 298 K (25 dc), 1.0 moldm-3
Define: 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
Define: Enthalpy change of reaction
The enthalpy change that accompanies a reaction in molar quantities expressed in a chemical equation under standard conditions, all substances being in their standard states
Define: Enthalpy change of combustion
The enthalpy change that takes place when one mole of a substance completely reacts with oxygen under standard conditions, all substances being in their standard states
Define: Average bond enthalpy
The average enthalpy change that takes place when breaking by homolytic fission 1 mol of a given type of bond in the molecules of a gaseous species
Define: Catalyst
A substance which speeds up a reaction without being consumed by the overall reaction
State: Le Chatiliers principal
If a a change is made to a system in dynamic equilibrium then the position of the equilibrium shifts to counteract the change
Emperical Formula
The smallest whole number ratio of atoms of each element in a compound
Molecular formula
The actual number of atoms of each element present in a compound
Displayed formula
the relative positioning of atoms and their bonds
