Keywords Flashcards
Addition reaction
Reaction where a molecule joins to an unsaturated molecule to produce a saturated molecule
Aliphatic
Organic compounds containing C chains and branches
Aromatic
Organic compounds containing one or more benzene ring(s)
Carbocation
A positive ion with the positive charge on a C atom
Cyclic
Organic compounds containig C rings(not aromatic rings) also called alicyclic
Dehydration
Elimination of water
Dehydrogenation
Elimination of hydrogen
Electrophile
An electron deficient atom, ion or molecule that take part in an organic reaction by attacking areas g high electron density in another reactant
Elimination reaction
Reaction where a molecule is lost from a saturated molecule to form an unsaturated molecule
Free radical
Species with an unpaired electron
Functional group
The atom or group of atoms that is responsible for most of the chemical reactions of a molecule
Homologous series
A family of compounds with the same general formula and similar chemical properties. In a series, each member differs by the addition of a CH2 group and there is a gradual change in physical properties
Hydration
Addition of water
Hydrocarbon
Molecule containing hydrogen and carbon only
Hydrogenation
Addition of hydrogen
Hydrolysis
A reaction involving the breaking of bonds due to reaction with water
Nucleophile
An ion or group of atoms with a negatively charged or partially negatively charged area that takes parts in an organic reaction by attacking an electron deficient area in another reactant
Organic chemistry
Study of compounds containing carbon
Saturated
Molecule containing no double bonds
Stereoisomers
Molecules with the same molecular and structural formulae but different spatial arrangement of atoms
Geometric isomers
Type of stereoisomerism: molecules which have different arrangement of groups around C=C
Optical isomers
Type of stereoisomerism: molecules which are non-superimposable mirror images
Structural isomers
Molecules with the same molecular formula but different structures
Chain isomers
Type of structural isomerism: structural isomers that differ by having a different carbon chain
Position isomers
Type of structural isomerism: structural isomers that differ by having the fuctional group in a different position
Functional group isomers
Type of structural isomerism: structural isomers that differ by having a different functional group
Substitution reaction
Reaction where an atom/group replaces another atom/group
Unsaturated
Molecule containing double bond(s)
Primary haloalkane
A carbon joined to a halogen and only one other alkyl group
Secondary haloalkane
A carbon joined to a halogen and two other alkyl groups
Tertiary haloalkane
A carbon joined to a halogen and three other alkyl groups
Alkyl
Groups, often attached to organic compounds, derived from alkanes with a missing H.
Polar
The description of a molecule in which the charge is not equally distributed. One area is slightly positively charged and the other is slightly negatively charged
Electronegativity
The ability of atoms to pull electrons towards themselves in a covalent bond
Covalent bond
Describes a chemical bond in which electrons are shared between two atoms
Ionic bond
Describes a chemical bond in which an electron is lost or gained resulting in oppositely charged ions with electrostatic forces of attraction between them
Intermolecular forces
Forces between molecules
Molecular formula
The actual number of atoms of each element in one molecule of the compound
Empirical formula
The formula that represents the simplest ratio of the atoms of each element present in a compound
Complete combustion
Oxidation of alkanes with plenty of oxygen and the only products are carbon dioxide and water
Fuel
A substance that burns exothermically
Cracking
The breaking of long alkane chains into shorter more useful chains some of which are alkenes
Global warming
An increase in the temperature of the Earth’s surface
Greenhouse gas
A gas that absorbs long wavelength infrared radiation given off by the Earth but does not absorb the Sun’s radiation
Halide
Group 7 ion
Petroleum Fraction
Mixture of hydrocarbons collected over a particular range of boiling points during the fractional distillation of crude oil
Petroleum
A mixture consisting mainly of alkane hydrocarbons
Enthalpy
A measure of the heat content of a substance
Enthalpy change
The energy change at a constant pressure
Exothermic
A reaction where at the end of the reaction, energy has been given out
Endothermic
A reaction where at the end of the reaction, energy has been taken in
Activation Energy
The minimum amount of kinetic energy that particles need to react; the energy difference between the reactants and the transition state
Standard enthalpy of formation
The enthalpy change when 1 mole of a compound is formed from its elements with all substances in their standard states under standard conditions
Standard enthalpy of combustion
The enthalpy change when 1 mole of a compound is completely burnt in oxygen under standard conditions and all the reactants and products in their standard states
Standard enthalpy of neutralisation
The enthalpy change when 1 mole of water is formed in a reaction between an acid and alkali under standard conditions
Standard enthalpy of reaction
The enthalpy change for a reaction with the quantities shown in the chemical reaction. This means that the value should always be quoted along with the reaction
Specific heat capacity
The amount of energy it takes to raise the temperature of 1g of a substance by 1K
Alkaline earth metals
The metals in group 2 of the periodic table
Aldehyde
An organic compound with the general formula RCHO in which there is a C=O double bond
Alkane
A hydrocarbon with C-C and C-H single bonds only, with the general formula CnH2n+2
Allotropes
Pure elements which can exist in different physical forms in which their atoms are arranged differently. For example, diamond, graphite and buckminsterfullerene are allotropes of carbon
Anaerobic respiration
The process by which the energy is released and new compounds formed in living things in the absence of oxygen
Atomic economy
This describes the efficiency of a chemical reaction by comparing the total number of atoms in the product with the total number of atoms in the starting materials
Atomic orbital
A region of space around an atomic nucleus where there is a high probability of finding an electron
Avogadro constant
The total number of particles in a mole of a substance. Also called the Avogadro number. it is equal to 6.022*10^23
Bond dissociation enthalpy
The enthalpy change required to break a covalent bond with all species in the gaseous state
Calorimeter
An instrument for measuring the heat changes that accompany chemical reactions
Catalyst
A substance that alters the rate of a chemical reaction but is not used in the reaction
Catalytic cracking
The breaking, with an aid of a catalyst, of long-chained alkanes into shorter chain hydrocarbons some of which are alkenes
Carbon-neutral
A process, or series of processes, in which as much carbon dioxide is absorbed from the air as is given out
Chemical feedstock
The starting materials in an industrial chemical process
Co-ordinate bonding
Covalent bonding in which both the electrons in the bond come from one of the atoms in the bond - also called dative covalent bonding
Delocalised electrons
Describes electrons that are spread over several atoms and help to bond them together
Dipole-dipole force
An intermolecular force that results from the attraction between molecules with permanent dipoles
Displayed formula
The formula of a compound drawn out so that each atom and each bond is shown
Disproportionation
Describes a redox reaction in which the oxidation number of some atoms of a particular element increases and that of other atoms of the same element decreases
Dynamic equilibrium
A situation in which the composition of a reaction mixture does not change because both forward and backward reactions are proceeding at the same rate
Electron density
The probability of an electron being found in a particular volume of space
Electron pair repulsion theory
A theory which explains the shapes of simple molecules by assuming that pairs of electrons around a central atom repel each other and thus take up positions as far away as possible from each other in space
Electrophilic addition
A reaction in which a carbon-carbon double bond is saturated and in which the initial reaction is an attack by an electrophile
Electrostatic forces
The forces of attraction and repulsion between electrically charged particles
Elimination
A reaction in which an atom or group of atoms is removed from a reactant
Enthalpy diagrams
Diagrams in which the enthalpies of the reactants and products of a chemical reaction are plotted on a vertical scale to show their relative levels
Equilibrium mixture
The mixture of reactants and products formed when a reversible reaction is allowed to proceed in a closed container until no further change occurs. The forward and backward reactions are still proceeding but at the same rate
Fingerprint region
The area of an infra-red spectrum below about 1500cm. It is caused by complex vibrations of the whole molecule and is characteristic of a particular molecule
Group
A vertical column of elements in the periodic table, The elements have similar properties because they have the same outer electron arrangement
Half equation
An equation for a redox reaction which considers just one of the species involved and shows explicitly the electrons transferred to and from it
Heterogeneous catalyst
A catalyst which is in a different phase from the reactants. For example, iron in the haber process conversion of nitrogen and hydrogen to ammonia
Homogeneou catalyst
A catalyst which is in the same phase as the reactants
Hydrogen bonding
A type of intermolecular force in which a hydrogen atom covalently bonded to an electronegative atom interact with another electronegative atom
Incomplete combustion
A combustion reaction in which there is insufficient oxygen for all the carbon in the fuel to burn to carbon dioxide. Carbon monoxide and/or soot are formed
Ionic bonding
Describes a chemical bond in which an electron or electrons are transferred from one atom to another, resulting in the formation of oppositely charged ions with electrostatic forces of attraction between them
Ketone
An organic compound with the general formula R2CO in which there is a C=O double bond
Lattice
A regular three dimensional arrangement of atoms, ions or molecules
Leaving group
An atom or group of atoms that is rejected from the stating material, normally taking with it an electron pair and forming a negative ion
Lone pair
A pair of electrons in the outer shell of an atom that is not involved in bonding. Also called an unshared pair
Maxwell-Boltzmann distribution
The distribution of energies(and therefore speeds) of the molecules in a gas or liquid
Mean bond enthalpy
The average value of the bond dissociation enthalpy for a given type of bond taken from a range of different compounds
Metallic bonding
Describes a chemical bond in which the outer electrons are spread over a lattice of metal ions in a delocalised system
Mole
A quantity of a substance that contains the Avogadro number of particles
Molecular ion
A molecule of the sample which has been ionised but which has not broken up during its flight through the mass spectrometer
Monomer
A small molecule that combines with many other monomers to form a polymer
Nucleon
Protons and neutrons found in the nuclei of atoms
Nucleophilic substitution
An organic reaction in which a molecule with a partially positively charged carbon atom is attacked by a reagent with a negative charge or partially negative charge. It results in the replacement of one of the groups or atoms on the original molecule by the nucleophile
Nucleus
Thee tiny, positively charged centre of an atom composed of protons and neutrons
Oxidation
A reaction in which an atom or group of atom loses electrons
Oxidation state
The number of electrons lost or gained by an atom in a compound compared to the uncombined atom. It forms the basis of a way of keeping track of redox reactions
Oxidising agent
A reagent that oxidises another species
Percentage yield
The actual amount of product produced divided by the theoretical amount expressed as a percentage
Period
A horizontal row of elements in the periodic table. there are trends in the properties of the elements as we cross a period
Periodicity
The regular recurrence of the properties of elements when they are arranged in atomic number order in the periodic table
Positive inductive effect
Describes the tendency of some atom or group of atoms to release electrons via a covalent bond
Proton number
The number of protons in the nucleus of an atom
Redox reaction
It describes reactions in which electrons are transferred from one species to anothe
Reducing agent
A reagent that reduce (adds electron to) another species
Reduction
A reaction in which an atom or group of atoms gain electrons
Spectator ions
Ions that are unchanged during a chemical reaction, i.e. they take no part in the reaction
Stoichiometry
Describes the simple whole number ratios in which chemical species react
Strong nuclear force
The force that holds protons and neutrons together in the nucleus of the atom
Structural fomula
A way of writing the formula of an organic compound in which bonds are not shown but each carbon atom is written separately with the atom or group of atoms attached to it
Thermochemical cycle
A sequence of chemical reactions that convert a reactant into a product. The total enthalpy change of the sequence of reactions will be the same as that for the conversion of the reactant to the product directly
van der Waals forces
A type of intermolecular force of attraction that is caused by instantaneous dipoles and acts between all atoms and molecules
Relative atomic mass
The average mass of an atom of an element on a scale where an atom of carbon 12 is 12
Relative molecular mass
The average mass of a molecule on a scale where an atom of carbon 12 is 12
Relative isotopic mass
The mass of an atom of an isotope of an element on a scale where an atom of carbon 12 is 12
Isotope
Atoms of an element which have the same number of protons but different number of neutrons
