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AS - KeyWords
AQA AS Chemistry
83
Chemistry
11th Grade
02/25/2014

Additional Chemistry Flashcards

 


 

Cards

Term

 

 

 

Activation Energy

Definition

 

 

The minimum energy that a particle needs in order to react: the energy (enthalpy) difference between the reactants and the transition state.

Term

 

 

 

Aldehyde

Definition

 

 

 

An organic compound with the general formula RCHO in which there is a C=O double bond.

Term

 

 

 

Alkaline Earth Metals

Definition

 

 

 

The metals in group two of the periodic table.

Term

 

 

 

Alkane

Definition

 

 

A hydrocarbon with C-C and C-H single bonds only.

With the general Formula CnH2n+2

Term

 

 

 

Allotropes

Definition

 

 

Pure elements which can exist in different forms in which their atoms are arranged differently.

For example Diamond and Graphite are allotropes of Carbon

Term

 

 

 

Anaerobic Respiration

Definition

 

 

The process by which energy is released and new compounds formed in living thims in the absence of oxygen.

Term

 

 

 

Atom Economy

Definition

This describes the efficiency of a chemical reaction by comaring the total number of atoms in the product with the total number of atoms in the reactants.

 

Mass of Desired Product x100 =% Atom Economy 

Total mass of reactants                                    

Term

 

 

 

Atom Orbital

Definition

 

 

A region of space around an atomic nucleus where ther is a high probability of finding an electron

Term

 

 

 

Bond Dissociation Enthalpy

Definition

 

 

The enthalpy change required to break a covalent break a covalent bond with all species in a gaseous space.

Term

 

 

Calorimeter

Definition

 

 

An instrument for measureing the heat changes that accompant chemical reactions.

Term

 

 

 

Catalyst

Definition

 

 

A substance that alters the rate of a chemical reaaction but is not used up in the reaction.

Term

 

 

 

Catalytic Cracking

Definition

 

 

The breaking, with the aid of the catalyst, of a long chain alkane molecules (obtained from crude oil) into shorted chained hydrocarbons some of which are alkenes.

Term

 

 

 

Carbocations

Definition

 

 

 

An organic ion in hich one of the carbon atoms has a positive charge.

Term

 

 

 

Carbon-neutral

Definition

 

 

 

A process, or series of processes in which as much carbon dioxide is absorbed from the atmosphere as is given out.

Term

 

 

 

Chemical Feedstock

Definition

 

 

 

The starting materials in an inductrial chemical reaction.

Term

 

 

 

Co-ordinate bonding

Definition

 

 

Covalent bonding when both the electrons in the bond come from one of the atoms in the bond.

(Also called dative-covalent)

Term

 

 

 

Covalent Bonding

Definition

 

 

Describes a chemical bond between two non-metal elements, in which a pair of electrons are shared between each element.

Term

 

 

 

Cracking

Definition

 

 

 

The breaking of long chain alkanes molecules into shorter chain hydrocarbons.

Term

 

 

 

Dative-Covalent Bonding

Definition

 

 

Covalent bonding when both the electrons in the bond come from one of the atoms in the bond.

(Also called Co-ordinate bonding)

Term

 

 

 

Avogadro Constant

Definition

 

 

The total number of Particles in a mole of a substance. 

6.022x1023

Term

 

 

 

Delocalised

Definition

 

 

 

Describes electrons that are spread over several atoms to help the bond together.

Term

 

 

 

Dipole-Dipole Force

Definition

 

 

An intermolecular force that results from the attraction between molecules with permanent dipoles.

Term

 

 

 

Displacement Reaction

Definition

 

A chemical reaction in which one atom or group of atoms replaces another in a compound, for example

 

Zn +CuO → ZnO + Cu

Term

 

 

 

Displayed Formula

Definition

The formula of a compound drawn out so that each atom and each bond is shown.

Example:

Term




Disproportionation

Definition

 

 

Describes a redox reaction in which the  oxidation number if some atoms of a particular element increases and that of other atoms of the same element decreases.

Term

 

 

 

Dynamic Equilibrium

Definition

 

 

A situation in which the composition of a reaction mixture does not change because both the forward and backwards reactions are occuring at the same rate.

Term

 

 

 

Electron Density

Definition

 

 

 

The probability of an electronbeing found in a particular volume or space.

Term

 

 

 

Electron Pair Repulsion Theory

Definition

 

A theory which explains the shapes of simple molecules by assuming that pairs of electrons around a central atom replel each other and thus take up positions as far away from each other as possible.

Term

 

 

 

Electronegativity

Definition

 

 

 

The power of an atom to attract the electrons in a covalent bond.

Term

 

 

 

Electrophile

Definition

 

 

An electron-deficient atom, ion or molecule that takes part in an organic reaction by attacking areas of high elctron density in another reactant.

Term

 

 

Electrophillic Addition

Definition

 

 

A reaction in which a C=C Double bond is saturated and in which the initial reaction is an attack by an electrophile.

Term

 

 

 

Electrostatic Forces

Definition

 

 

The forces of attraction and repulsion between electrically charged particles.

Term

 

 

 

Elimination

Definition

 

 

 

A reaction in which an atom or group of atoms is removed from a reactant.

Term

 

 

 

Empirical Formula

Definition

 

 


The simplest whole number ratio in which the atoms in a compound combine together.

Term

 

 

 

Endothermic

Definition

 

 

Describes a reaction in which heat is take in as the reactant change to products; the temperature of the surrounding drops.

Term

 

 

 

Enthalpy Change

Definition

 

 

A measure of heat energy given out or taken in when a chemical or physical change occurs at constant pressure.

Term

 

 

 

Enthalpy Diagrams

Definition

 

Diagrams in which the epthalpys (energies) of the reactants and products of a chemical reaction are plotted on a vertical scale to show their relative levels

Term

 

 

 

Equilibrium Mixture

Definition

 

The Mixture of reactants and products formed when a reversible reaction is allowed to proceed in a close system until no further change occurs. The forward and backward reactions are still proceeding but at an equal rate.

Term

 

 

Exothermic

Definition

 

 

Describes a reaction in which heat is given out as the reactant change to products; the temperature of the surrounding rises.

Term

 

 

 

Fingerprint Region

Definition

 

 

The area of an infrared spectrum below about 1500cm-1. It is caused by complex vibrations of the whole molecule and is characteristic of a particular molecule.

Term

 

 

 

Fraction

Definition

 

 

A mixture of hydrocarbons collected over a particular range of bp's during the fraction distillation of crude oil.

Term

 

 

 

Free Radical

Definition

 

 

 

A chemical species which an unpaired electron - usually highly reactive.

Term

 

 

 

Functional Group

Definition

 

 

An atom or group of atoms in an organic molecule which is responsable for the characteristic reaction of that molecule.

Term

 

 

 

Group

Definition

 

 

A vertical column of elements in the periodic table. The elements have similar properties because the same outer electron arangement.

Term

 

 

 

Half Equation

Definition

 

 

An equation for a redox reaction which considers just one of the species involved and show explicitly the electrons transferred to or from it.

Term

 

 

 

Heterogeneous Catalyst

Definition

 

A catalyst which is in a different phasefrom the reactants. For example, Iron(s) in the Haber preccess Cinversion of Nitrogen(g) and hydrogen(g) to ammonia.

Term

 

 

 

Homogeneous Catalyst

Definition

 

 

 

A catalyst which is in the same phase as the reactants.

Term

 

 

 

Homologeous Series

Definition

 

A series which is a set of organic compounds whoch the same functional group. The compounds differ in the length of their hydrocarbon chains.

Term

 

 

 

Hydrogen Bonding

Definition

A type of intermolecular force in whch a hydrogen atom covalently bined to an electronegative atom.

 

NOF!!!

Term

 

 

 

Incomplete Combustion

Definition

 

 

A combustion reaction in which there is insufficient oxygen for all the carbon in the fuel to burn to CO2. CO and/or C (soot) are formed.

Term

 

 

 

Ionic Bonding

Definition

 

Describes a chemical bond between a metal and a non-metal in which an electron or electrons are transfered from the metal to the non-metal, resulting in the formation of oppositly charges ions hich electrostatic forces of attraction between them.

Term

 

 

 

Ionisation Energy

Definition

 

 

The energy required to remove a mole of electrons from a mole of isolated gaseous atoms or ions.

Term

 

 

 

Isomer

Definition

One (Or more) compounds with the same molecular formula but differen structural formula.

Ie : The same Atoms are arranged differently in space.

Term

 

 

 

Ketone

Definition

 

 

An organic compound with the general formula R2CO in which there is a C=O double bond.

Seconday Alcohol Oxidation.

Term

 

 

 

Lattice

Definition

 

A regular 3D arrangement of atoms, ions or molecules

 

Eg. Macromolecular

Term

 

 

 

Leaving Group

Definition

 

In an organic substitution reaction from a believing group is an atom or group of atoms that is ejected from the starting material, normally taking with it an electron pair and forming a negative ion.

Term

 

 

 

Lone Pair

Definition

 


A pair of electrons in the outer shell of an atom that is not involved in bonding, also called an unshared pair.

Used in a dative-covalent bond.

Term

 

 

 

Maxwel-Boltzmann Distribution

Definition

 

 

 

The distribution of energies (and therfore speed) of the molecules in a gas or liquid.

Term

 

 

 

Mean Bond Enthalpy

Definition

 

 

The average value of the bond dissociation enthalpy for a given type of bond taken froma range of different compounds.

Term

 

 

 

Metallic Bonding

Definition

 

Describes a chemical bond in which out electrons are spread over a lattice of metal ions in a delocalised system.

 

 

Term

 

 

 

Mole

Definition

 

A quantity of a substance that contains the advogadro's constant (6.022x1023) of particals (eg. Atoms, molecules or Ions)

Term

 

 

 

Molecular Formula

 

Definition

 

 

A formula that tells us the numbers of atoms of each different element that makes up a molecule of a compound.

Term

 

 

 

Molecular Ion

Definition

 

 

In mass spectrometery this a molecule of the sample which has been ionised but which has not broken up during its flight through an instrument.

Term

 

 

 

Monomer

 

 

 

Definition

 

 


A small molecule that combines with many other monomer a polymer.

Term

 

 

 

Nucleons

 

Definition

 

 

 

Protons and neutrons - the sub-atomic particles nuclei of atoms.

Term

 

 

 

Nucleophile

 

 

 

 

Definition

 

An ion or group of atoms with a negative charge or a partically negative - charged area that takes part in an organic reaction by attackin an electron - deficient area in another reactant.

Term

 

 

 

Neucleaphillic Substitution

Definition
An organic reaction in whch a molecule with a partically positively charged carbon atom is attacked by a reagent with a negative charge or partially negatively charged area (an nucleophile) It results in the replacement of one of the groups or atoms from the original molecule by the nucleophile.
Term

 

 

 

Nucleus

Definition

 

 

 

The tiny positively charged center of an atom composed of Protons and Neutrons.

Term

 

 

 

Oxidation

Definition

 

 

A reaction in which an atom or group of atoms loses electrons.

Term

 

 

 

Oxidation State

Definition

 

The number of electrons lost or gained by an atom in a compound compared ot the uncombined atom. It forms the basis of a way  keeping track of redox (electronic transfer) reactions. Also called Oxidation number.

Term

 

 

 

Oxidising Agent

Definition

 

 

 

A reagent thaat oxidises (removes electron from) another species.

Term

 

 

 

Percentage Yeild

Definition

 

 

In a chemical reaction, this is the actual amount of product produced, divided by the theoretical yeild (predicted from the chemical equation) expressed as a %.

Term

 

 

 

Period

Definition

 

 

A horizontal row of elements in the periodic table. There are trends in the properties as we go across the period.

Term

 

 

 

Periodicity

 

Definition

 

 

The regualr occurance of the properties of element when the are aranged in atomic number order as in the periodic table.

Term

 

 

 

Polar

Definition

 


Describes a molecule in which the charge is not symetrically distributed so that one area is slightly charged and another slightly negatively charged.

Term

 

 

 

Positive Inductive Effect

Definition

 

 

Describes the tendance of some atoms or groups of atoms to release electrons via a covalent bond.

Term

 

 

 

Proton Number

Definition

 

 

The number of protons in the nucleus of an atom; the same as the atomic number (z)

Term

 

 

 

Redox Reaction

Definition

 

 

Short for Reduction - Oxidation reasction, it describes reactions in which electrons are transfered from one species to another.

Term

 

 

 

Reducing Agent

Definition

 

 

 

A reagent that reduces (Adds electrons too) another species.

Term

 

 

 

Reduction

Definition

 

 

 

A reduction in which or group of atoms gains electrons.

Term

 

Relative Atomic Mass  (Ar)

 

 

Definition

 

 

Ar = Adverage mass of Molecule

        1/12 th mass of Carbon 

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