glossary f-n Flashcards
fermentation
a natural process that uses yeast enzymes to convert glucose to ethanol and carbon dioxide
filtrate
the purified liquid that collects in a flask when a mixture is filtered.
filtration
the process of removing solids from a liquid or gas by passing the mixture through a mesh or filter.
first ionization energy
the energy required to remove one electron from an atom of an element in the gas phase
flame test
determination of the metallic elements present in a compound by inserting a sample of the compound into a non-luminous bunsen burner flame.
Some metals produce a particular colours when heated.
formula
a representation of an element or compound using symbols for its constituent elements. It shows the RATIO of atoms in a compound or the number of atoms in a molecule.
fractional distillation
A form of distillation that separates solutions of liquids according to their boiling points.
fuel
substances that have chemical energy stored with them that can be released relatively easily.
full equation
a representation of a reaction that uses the formulae of all reactants and products in a chemical reaction.
fullerene
a molecule composed entirely of carbon, in the form of a hollow sphere or tube.
Each carbon is bonded to 3 other carbon atoms
gas chromatography GC
a very sensitive form of chromatography in which the mobile phase is a gas
(inert like N Ar etc )
geometric isomer
a type of stereoisomer that can occur when there is restricted rotation of a molecule ( = bond or ring ).
cis , trans used.
graphene
a form of carbon consisting of planar sheets one atom thick in which each carbon atom is bonded to 3 neighbouring atoms.
graphite
a form of carbon in which the carbon is arranged in layers.
ground state
a term used to describe an atom in which the electrons occupy the lowest possible energy levels.
group
A vertical column of elements in the periodic table.
Heat capacity
A measure of a substance’s capacity to absorb and store heat energy.
For water heat cap = 4.18 J C-1
or 1g of water given 4.18 J of energy will inc temp by 1 degree.
Heat of Combustion
The enthalpy change that occurs when a specific amount of a fuel burns completely in oxygen
Heat of Reaction
The exchange of heat between a system and its surroundings during a chemical reaction under constant pressure.
Symbol = ^H.
Also known as enthalpy change.
Heat treatment
Heating a metal in different ways to alter its structure and physical properties.
Heavy metal
A metal with high density, usually used to describe a metal that poses a threat to health.
Heterogenous
Different. A heterogenous substance or solution possesses two or more different types of phases in the one sample e.g. a suspension
High performance or High Pressure Liquid Chromatography HPLC
A very sensitive technique used to separate the components in a mixture, to identify each component and to measure the concentrations of the components.
Homogenous
Uniform, the same throughout.
The components of a homogenous substance are uniformly distributed throughout the substance
e.g. a solution
Homogenous catalyst
A catalyst that has the same physical state as the reactants and products.
Homologous Series
A series of compounds with similar properties and the same general formula, in which each member contains one CH2 unit more than the previous member.
Hydrated
An ion surrounded by water molecules.
Hydrated ions can be found in aqueous solution or crystalline solids.
Hydride
A compound in which hydrogen is bonded to another element.
HF, HCl, HI are hydrides of group 17 elements.
Hydrocarbon
A compound that contains carbon and hydrogen only.
e.g. alkanes, alkenes, alkynes
Hydrogen bonds
A type of inter-molecular, dipole-dipole force where a hydrogen atom is covalently bonded to a highly electronegative atom such as F, O, N.
The hydrogen develops a positive charge and bonds to another lone pair.
Hydronium ion
The H3O+ (aq) ion.
hydroxide ion
the OH - ion.
Hypothesis
A prediction based on previous knowledge, a possible outcome of an experiment
Ideal gas
A gas that obeys the gas equation at all temperatures and pressures. An ideal gas is a theoretical gas in which there are no intermolecular attractive forces and the gas particles have no volume.