C2.5 Synthesis Flashcards
polymer
Large molecule made by linking together many small molecules (monomers).
thermosetting
A polymer that cannot be melted or remoulded again once formed.
fraction
A constituent part of crude oil produced by fractional distillation.
addition
In polymer chemistry, a large molecule formed from alkene monomers added together to form chains.
alkene
A hydrocarbon in which two or more carbon atoms are joined by double bonds.
displayed formula
A diagram of the structure of a molecule in which the elements are represented by letters and the bonds are shown by straight lines.
atom economy
The proportion of reactants that are converted into useful products.
hydrocarbon
An organic compound containing just hydrogen and carbon.
toxic
Poisonous. Toxic substances may cause death if they are swallowed, breathed in or come into contact with the skin.
saturated hydrocarbon
A compound of hydrogen and carbon in which there are only single bonds. Alkanes are saturated hydrocarbons.
percentage yield
The percentage of a theoretical yield that you actually get in a reaction.
sustainable development
Meeting the needs of the existing population without damaging the ability of future generations to meet their own needs.
fractional distillation
An industrial process used to separate the constituent parts of crude oil.
synthesis
Making a substance using chemical reactions.
unsaturated monomer
A small molecule that can form a polymer because it contains a double bond.
plasticiser
A substance added to polymers to make them softer and more flexible. Plasticisers allow polymer chains to slide over each other more easily.
condensation
A type of reaction in which two molecules join together to make a larger one, with water as a by-product.
double bond
Two covalent bonds between two atoms, involving two shared pairs of electrons.
formula
An abbreviation for a substance with two or more atoms. The formula contains the symbols for the different elements in the substance, with numbers to show if there are two or more atoms of a particular element present.
repeating unit
A section or monomer of a polymer which shows its structure.
polymerisation
In chemistry the process by which small alkenes (monomers) join together to form large molecules (polymers).
thermoplastic
A polymer that softens or melts when heated and becomes hard again when cooled.
toxicity
How toxic or poisonous a substance is. Very toxic substances have a high toxicity.
state symbol
Symbol used in chemical equations to show whether a substance is solid (s), liquid (l), gas (g) or dissolved in water (aq).
theoretical yield
The maximum calculated amount of product that can be obtained from a particular quantity of reactants. Also called expected yield.
empirical
Worked out from an experiment. An empirical formula is worked out dividing the mass of each element in a compound by its relative atomic mass.
expected yield
See theoretical yield.
hydrogenate
To react with hydrogen.
polyunsaturated
A substance (usually a fat) that has more than one double bond.
viscous
Sticky or thick. Liquids with high viscosity are difficult to pour.
cross-links
Strong covalent bonds that form between polymer molecules.
monounsaturated
A substance (usually a fat) that only has one double bond.
monomer
A small molecule, for example an alkene, that can be joined to many other small molecules to form a much larger molecule.
biodegradable
Able to be broken down by soil bacteria.
covalent bond
A type of chemical bond in which a pair of electrons is shared between two atoms.
alkane
A hydrocarbon in which all the bonds between the carbon atoms are single bonds.
relative formula mass
The mass of a molecule relative to the mass of a carbon atom. Abbreviated to Mr.
relative atomic mass
The mass of an atom compared to the mass of a carbon atom, which has a relative atomic mass of 12. Abbreviated to Ar.
molecular formula
A chemical code that shows how many of each atom there are in a molecule.
actual yield
The amount of product obtained from a chemical reaction in reality. This may differ from the theoretical or expected yield because the raw materials may not be pure or because the reaction may not be complete.
cracking
A type of chemical reaction in which large alkane molecules are decomposed to form smaller alkanes and alkenes.
unsaturated hydrocarbon
A compound of hydrogen and carbon in which there is one or more double bond. Alkenes are unsaturated hydrocarbons.
raw material
A starting substance for the manufacture of a particular chemical.
