Key Terms Paper 2 Flashcards
Define catalyst
Substance which speeds up the ROR
by lowering its activation energy
without itself being altered or used up
Define alkane
Saturated hydrocarbon containing only hydrogen and carbon atoms
Define alkene
Unsaturated hydrocarbon with a C=C double bond
Define exothermic
When energy is transferred to the surroundings
(Energy EXits)
More energy released in making bonds than used to break them (MEXO) - net energy decrease
Define endothermic
When energy is absorbed from the surroundings
More energy needed to break bonds than released when bonds are made (BENDO) - net energy increase
Define bitumen
The most viscous fraction of crude oil used to surface roads
Define kerosene
A relatively light fraction of crude oil
obtained through fractional distillation
used as a fuel in aviation
Define saturated
Molecule containing only single bonds
e.g. Alkanes
Define unsaturated
Molecule containing at least one double bond
e.g. Alkenes
Define allotrope
Different physical forms of the same element in the same physical state but with different structure and properties
e.g. Diamond and Graphite and carbon allotropes
Define carbon allotrope
A different form of carbon that has the same chemical composition but different physical properties
Define activation energy
minimum amount of energy required for a chemical reaction to occur
Define covalent bond
A shared pair of electrons between two non-metal atoms
Define turbidity
Measure of a liquid’s transparency
e.g. when the ‘x’ is covered as adding sodium thiosulphate to HCl causes the solution to go cloudy (have a higher turbidity)
Define polymer
A large molecule made up of repeating units called monomers
Define addition polymerisation
Chemical reaction in which monomers with a C=C join to form a single large molecule (a polymer)
No byproducts
Define condensation polymerisation
a chemical reaction where two monomers join to form a larger polymer molecule
simultaneously releasing a small molecule like water as a by-product
Define cracking
Process in which a long-chain hydrocarbon is broken down into shorter, more useful hydrocarbons - an alkane and an alkene
Define fractional distillation
Process of separating different lengths of hydrocarbons found in the mixture crude oil
Define catalytic cracking
Method of breaking long-chain alkanes in the presence of a (zeolite) catalyst at 550°C
Define steam cracking
Method of breaking long-chain alkanes without a catalyst at over 800°C
Define zeolite catalyst
The catalyst used to break down long-chain alkanes in catalytic cracking
Define soot
Carbon particulates as a result of incomplete combustion
Define ‘in excess’
There will always be some of that reactant left over as the other reactant is the limiting factor
More is present than is needed to react fully with other reactants
Define precipitate
An insoluble solid which forms when two soluble substances are mixed
Define solution
A mixture of two or more substances where one has dissolved into another
Define monomer
A small, reactive molecule
Define intermolecular forces
Weak, attractive forces between molecules
Inter - think interfaith dialogue
Define nanotubes
Very small Cylindrical fullerenes resembling graphene
Define fullerene
Hollow, spherical or cylindrical carbon molecules
Define homologous series
A group of organic compounds with the same general formula and similar chemical properties
Define functional group
A group of atoms which determine a molecule’s chemical properties
Molecule - two or more atoms chemically bonded
Define alcohol
An organic compound with a hydroxyl group
Organic compound - a carbon-based compound
Compound - two or more different elements chemically bonded
Define carboxylic acid
Compounds containing the carboxyl functional group (-COOH)
Define ester
Compounds with the functional group -COO- formed by a condensation reaction between a carboxylic acid and an alcohol
Define giant covalent structure
A large number of atoms joined by strong covalent bonds
Define diamond
A giant covalent structure of carbon in a rigid lattice structure
Carbon atoms form 4 bonds
Not a fullerene because its not hollow
Define graphite
A giant covalent structure of carbon atoms arranged in hexagons in sheets
Carbon atoms form 3 bonds
Define graphene
One layer of graphite
A giant covalent structure of carbon
Define halogen
A non-metal element in group 7 of the periodic table
Define halide ion
A negative ion formed when a halogen gains an electron
Define alkali metal
Group 1 elements
Define noble gas
Inert group 0 elements
Define hydrocarbon
A compound only made of hydrogen and carbon atoms
Define crude oil
A mixture of hydrocarbons
formed from the remains of ancient organisms
Define solute
A substance that dissolves in a solvent to form a solution
Define solvent
The liquid in which a substance (the solute) dissolves
Define molecule
Two or more atoms chemically bonded
e.g. O2
All compounds are molecules but not all molecules are compounds
Define compound
Two or more different elements held together by chemical bonds
All compounds are molecules
(But not all molecules are compounds)
Define organic compound
A carbon based compound
Compound - Two or more different elements held together by chemical bonds
Define simple molecular substance
a substance formed when two or more atoms are covalently bonded together
