Key definitions Flashcards
Acid
A proton donor. It reacts with bases to form salt and water
Acidic oxide
An oxide that reacts with a base to form a salt and water
Acid rain
Rain with a ph. below 5.6 due to the reaction of acidic gases and rain water
Activation energy
The minimum energy required for particles to react when they collide
Addition polymerisation
A reaction in with monomers containing c=c double bonds react to form polymers without any other substance being formed.
Addition reaction
In organic chemistry, a reaction where two molecules combine to give a single product
Alcohol
A compound containing the -OH functional group, having the new general formula CnH2n+1OH
Alkali
A soluble base
Alkali metals
The elements in group 1 of the periodic table
Alkane
A hydrocarbon with only single bonds
Alkene
A hydrocarbon with one or more double bonds
Alloy
A mixture of a metal with another element or elements
Amphoteric oxide
An oxide that reacts with both acids and bases to form a salt and water
Anhydrous (salts)
Salts without any water of crystallisation
Anion
A negative ion
Anode
The positive electrode
Anomalous result
A result or piece of data that does not fit the pattern of the rest of the data
Atom
The smallest part of an element that can take part in chemical change
Avogadro constant
The number of defined particles in one mole of those particles
Base
A proton acceptor. It reacts with acids to form a salt and water
Basic oxide
An oxide that reacts with an acid to form a salt and water
Bond energy
The energy needed to break one mole of covalent bonds between two particular atoms
Brownian motion
The random movement of small visible particles in a suspension caused by unequal random bombardment of molecules of liquid or gas on the visible particles.
Carbohydrates
The general name for simple and complex sugars having the general formula Cx(H2O)y
Carbon cycle
The cycle of processes which move carbon compounds between the earth, atmosphere, and ocean and keeps the amount of carbon dioxide to be fairly consistent in the atmosphere
Carboxylic acid
A compound containing the -COOH functional group, having the general formula CnH2n+1 COOH
Catalyst
A substance which speeds up a chemical reaction but is never used up or changed
Catalytic converter
A device fitted onto a car exhaust system to reduce the emission of oxides of nitrogen and carbon monoxide.
Cathode
The negative electrode
Cation
A positive ion
Chemical change
How elements and compounds react with other substances
Compound
A substance made up of two or more different atoms (or ions) bonded together
Concentration (of solution)
The amount of solute dissolved in a defined volume of solution
Condensation polymerisation
A reaction where two organic molecules join together in a condensation reaction to form the repeating units of a polymer.
Condensation reaction
A reaction where two organic molecules join together with the elimination of a small molecule such as water
Condensing
The changing state when a gas changes to a liquid
Contact process
The industrial process of making sulfuric acid using vanadium (V) oxide catalyst and high tempurature.
Corrosion
The “eating away” of the surface of a metal by chemical reaction
Covalent bond
A bond formed by sharing a pair of electrons between two atoms
cracking
The process by which large, less useful hydrocarbon molecules are broken down into smaller, more useful alkanes and alkenes.
Delocalised electrons
Electrons which are not associated with any particular atom and are able to move between atoms and ions
Diatomic
molecule containing two atoms
Diffusion
The spreading movement of one substance into another due to the random motion of particles.
Displacement reaction
A reaction in which one atom or ion replaces another atom or ion in a compound
Ductile
Can be drawn into wires by a pulling force
electrochemical cell
A source of electrical energy where two metals of different reactivity dipping into an electrolyte are connected via an external circuit.
electrode
A rod of metal or graphite which leads an electric circuit to or from an electrolyte
electrolysis
the breakdown of an ionic compound by passage of electricity
electrolyte
An ionic compound which conducts electricity when molten or dissolved in water
electron shells
the regions at different distances from the nucleus where one or more electrons are found.
electronic arrangement
the number and arrangement of electrons in the electron shells of an atom
electroplating
the coating of the surface of one metal with a layer of another by an electrolytic reaction
element
A substance containing only one type of atom
empirical formula
A formula showing the simplest whole number ratio of atoms or ions in a compound
endothermic reaction
A reaction or process which absorbs energy
energy level diagram
a diagram showing the energy change of the reaction on the vertical axis and the reactants and products on horizontal axis
enzyme
a biological catalyst
equilibrium reaction
a reaction which does not go to completion and in which reactants and products are present in fixed concentration ratios at a particular tempurature and pressure
ester
a substance with the general formula RCOOR formed by the reaction between carboxylic acid and an alcohol
esterification
the reaction between a carboxylic acid and an alcohol to produce an ester and water
evaporation
the change in state from the liquid phase to the gaseous phase below the boiling point of a liquid
exothermic
a reaction or process which releases energy
fair test
an experiment where the independant variable affects the dependant variable and all other variables are controlled
fermentation
The breakdown of organic substances by microorganisms with effervescence and release of energy. It commonly refers to the breakdown of sugars by enzymes in yeast in the absence of oxygen to form ethanol.
filtrate
in filtration, the liquid which goes through the filter paper.
flame test
a test for a particular metal ion by heating a sample of a compound containing the ion and blue Bunsen flam. characteristic sulphur are burned
flue gas desulfurization
the removal of sulphur dioxide from wasted gases produced when fossil fuels containing sulphur are burned.
fraction
a group of molecules with a defined boiling point range which distils off at the same place during fractional distillation
