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88 Cards in this Set
- Front
- Back
Activation energy |
The minimum energy a particle needs in order to react. The energy (enthalpy) difference between the reactants and the transition state |
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Aldehyde |
An organic compound with the general formula RCHO in which there is a c=o bond (carbonyl group) |
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Alkaline earth metals |
Metals in group 2 |
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Alkane |
A hydrocarbon with single c-c and c-h bonds only. General formula of CnH2n+2 |
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Allotrope |
A pure element which can exist in different physical forms. Eg- diamond, graphite and buckminsterfullerene are all allotropes of carbon |
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Anaerobic respiration |
Process by which energy is released and new compounds fomed in living things without oxygen |
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Atom economy |
Describes the efficiency of a chemical reaction by comparing the total number of atoms in the product to those in the starting materials. %atom economy= mass desired product/mass of reactants X100 |
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Atomic orbital |
A region of space around an atomic nucleus where there is a high probability of finding an electron |
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Avogadro constant |
Total number of particles in 1 mole. |
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Avogadro's number |
6.022X10^23 |
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Bond disassociation enthalpy |
The enthalpy change required to break a covalent bond with all species in gaseous state |
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Calorimeter |
An instrument for measuring the heat changes that accompany chemical reactions |
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Catalyst |
Substance that alters the rate of a chemical reaction but is not used up in the reaction |
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Catalytic cracking |
The breaking, with the aid of a catalyst, of long chain molecules from crude oil into shorter chained mixed hydrocarbons |
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Carbocation |
An organic ion in which one of the carbon atoms has a positive charge. |
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Carbon-neutral |
A process, or series of processes in which as much CO2 is absorbed from the site as is given out. |
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Chemical feedstock |
The starting materials in an industrial chemical process |
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Co-ordinate bonding |
Covalent bonding in which both the electrons in the bond come from one of the atoms in the bond |
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Covalent bonding |
Describes a chemical bond in which electrons are shared between two atoms |
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Cracking |
The breaking of long chain hydrocarbons into shorter chain hydrocarbons |
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Delocalised |
Electrons that are spread over several atoms and help to bond them together |
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Dipole-dipole force |
An intermolecular force that results from the attraction between molecules with permanent dipoles |
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Displacement reaction |
A chemical reaction in which one atom or a group of atoms replaces another in a compound |
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Displayed formula |
The formula of a compound drawn out so that each atom and each bond is shown |
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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 |
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Dynamic equilibrium |
A situation in which the composition of a reaction mixture does not change because of both forward and backward reactions are proceeding at the same rate |
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Electron density |
The probability of an electron being found in a particular volume of space. |
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Election pair repulsion theory |
A theory which explains the shapes of simple molecules by assuming that pairs of electrons around a central atom repel racketeer and thus take up positions as far away as podunk from another in 3D space |
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Electronegativity |
The power of one atom to attract the pair of electrons in a covalent bond |
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Electrophile |
An electron-deficient atom, ion or molecule that takes part in an organic reaction by attacking areas of high electron density in another reactant |
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Electrophilic addition |
A reaction in which a c=c bond is saturated and in which the initial reaction is an attack by an electrophile |
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Electrostatic forces |
The forces of attraction and repulsion between electrically charged particles |
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Elimination |
A reaction in which an atom or group of atoms is removed from a reactant |
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Empirical formula |
The simplest whole number ratio in which the atoms in a compound combine |
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Endothermic |
A reaction where heart is taken in |
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Enthalpy change |
A measure of heat energy given out or taken in when a chemical or physical change occurs at a constant pressure |
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Enthalpy diagram |
A diagram on which the enthalpies of the products and reactants are plotted on a vehicle scale to show their relative levels |
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Equilibrium mixture |
The mixture of products and reactants formed when a reversible reaction is allowed to proceed in a closed container until no further change occurs. The forward and backward reactants are still processing but at the same rate |
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Exothermic |
Describes a reaction in which heat is given out. (Heat EXits) |
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Fingerprint region |
The area of infrared spectrum below about 1500cm^-1. It is caused by complex vibrations of the whole molecule and is characteristic of a particular molecule |
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Fraction |
A mixture of hydrocarbons collected over a particular range of boiling points during the fractional distillation of crude oil. |
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Free radical |
A chemical species with an unpaired electron-usually highly reactive |
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Functional group |
An atom or group of atoms in an organic molecule which is responsible for the characteristic reactions of that molecule |
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Group |
A vehicle column of the elements in the periodic table. They have similar properties as they all have the same outer electron arrangement. |
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Half equation |
An equation for a redox reaction which considers just one of the species involved and shows explicitly the electrons transferred to or from it |
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Heterogeneous catalyst |
A catalyst which is in a different phase from the reactants. Eg: iron in the haber process |
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Homogenous catalyst |
A catalyst which is in the same phase as the reactants |
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Homologous series |
A set of organic compounds with the same functional group. The compounds differ in the length of their hydrocarbon chains |
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Hydrogen bonding |
Strongest IMF where a hydrogen atom covalently bonded to a NOF interacts with another NOF |
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Incomplete combustion |
a combustion reaction where there is insufficient oxygen for all the carbon to form carbon dioxide so carbon monoxide is produced or just carbon |
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Ionic binding |
A chemical bond where electron(s) are transferred from one atom to another resulting in the formation of oppositely charged ions joined by strong electrostatic forces of attraction |
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Ionisation energy |
The energy required to remove a mile of electrons from a mole of isolated gaseous ions or atoms |
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Isomer |
One or two compounds with the same molecular formula but different structural formula |
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Ketone |
An organic compound with the general formula R2CO in which there is a C=O carbonyl group |
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Lattice |
A regular three dimensional arrangement of atoms ions or molecules |
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Leaving group |
In an organic substitution reaction, the leaving group is an atom or group of atoms that is ejected from the starting material, normally taking an electron pair and forming a negative ion |
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Lone pair |
A pair of electrons in the outer shell of an atom that is not involved in bonding |
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Maxwell-Boltzmann distribution |
The distribution of energies (and speeds) of the molecules in a had our liquid |
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Mean bond enthalpy |
The average value of the bond disassociation enthalpy for a given type of bond taken from a range of different compounds. |
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Metallic binding |
Describes a chemical bonds in which outer electrons are spread over a lattice of metal ions in a delocalised system |
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Mole |
A quantity of substance |
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Molecular formula |
A formula that treks us the numbers of atoms of each different element that make up a molecule in a compound |
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Molecular ion |
In mass spec this is a molecule of the sample which has been ionised and not broken up |
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Monomer |
A small molecule that combines with many other monomers to form a polymer |
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Nucleons |
Protons and neutrons |
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Nucleophile |
An ion or group of atoms with a negative charge or partially negative charged area that participates in an organic reaction by attacking an electron deficient area in another reactant |
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Nucleophilic sub |
Organ reaction where a molecule containing a partially charged positive carbon atom is attacked by a reagent with a negative charge |
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Oxidation |
Loss of electrons |
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Oxidation state |
The number of electrons lost or gained by an atom in a compound composite to an atom |
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Oxidising agent |
Reduces another species |
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Percentage yield |
Actual amount of product/theoretical amount X100 |
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Periodicity |
Regular reoccurrence of the properties of elements when they are arranged in the periodic table |
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Polar |
A molecule in which the charge is not symmetrically distributed |
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Positive induction effect |
Tendency of some atoms to release electrons via covalent bond |
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Redox reaction |
Electrons transferred from one species to another |
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Reduction |
Gain of electrons |
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Reducing agent |
Oxidises other reactant |
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Relative atomic mass |
Average mass of an atom / 1\12 mass of C12 atom |
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Relative formula mass |
Average mass of an entity / 1\12 mass C12 atom |
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Relative molecular mass |
Average mass of a molecule / 1\12 mass of C12 atom |
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Saturated hydrocarbon |
Only contains hydrogen and carbon with only single bonds |
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Specific heat capacity |
The amount of heat needed to raise the temperature of 1g of substance by 1k |
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Spectator ions |
Ions that are unchanged during the chemical reaction |
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Enthalpy change of combustion |
The amount of heat energy given out when 1 mile of a substance is completely burned in oxygen with all reactants and products in their standard states and conditions. |
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Enthalpy of formation |
Heat change when 1 mole of substance is formed from its elements in its standard states and conditions |
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Nuclear forces |
Forces that hold together protons and neutrons in the atoms nucleus |
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Structural formula |
A way of writing the formula of an organic compound in which bonds aren't shown but each carbon is written separately with the groups of atoms attached to it |
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Van der waals force |
An IMF that is caused by instantaneous dipoles and acts between All atoms and molecules |