OCR A Level Chemistry
acid - Answer-A species that is a proton donor.
activation energy - Answer-The minimum amount of kinetic energy that particles
need to have in order to react when they collide
addition polymer - Answer-A very long molecular chain formed by repeated
addition reactions of many unsaturated alkene molecules (monomers).
addition polymerisation - Answer-The process in which unsaturated alkene
molecules (monomers) add on to a growing polymer chain one at a time to form a
very long saturated molecular chain (the addition polymer).
addition reaction - Answer-A reaction in which a reactant is added to an
unsaturated molecule to make a saturated molecule.
adsorption - Answer-The process that occurs when a gas, liquid or solute is held to
the surface of a solid or, more rarely, a liquid.
alicyclic hydrocarbon - Answer-A hydrocarbon with carbon atoms joined together
in a ring structure.
aliphatic hydrocarbon - Answer-A hydrocarbon with carbon atoms joined together
in straight or branched chains.
alkali - Answer-A type of base that dissolves in water forming hydroxide ions, OH-
(aq) ions.
,alkanes - Answer-The homologous series with the general formula: CnH2n+2.
alkyl group - Answer-An alkane with a hydrogen atom removed, e.g. CH3, C2H5;
alkyl groups are often shown as 'R'.
amount of substance - Answer-The quantity whose unit of the mole. Chemists use
'amount of substance' as a means of counting atoms.
anhydrous - Answer-A substance that contains no water molecules.
anion - Answer-A negatively charged ion.
atom economy - Answer-atom economy = molecular mass of the desired product
×100 sum of molecular masses of all products
atomic orbital - Answer-A region within an atom that can hold up to two
electrons, with opposite spins.
atomic (proton) number - Answer-The number of protons in the nucleus of an
atom
acid - Answer-A species that is a proton donor.
activation energy - Answer-The minimum energy required to start a reaction by
the breaking of bonds.
, addition polymer - Answer-A very long molecular chain formed by repeated
addition reactions of many unsaturated alkene molecules (monomers).
addition polymerisation - Answer-The process in which unsaturated alkene
molecules (monomers) add on to a growing polymer chain one at a time to form a
very long saturated molecular chain (the addition polymer).
addition reaction - Answer-A reaction in which a reactant is added to an
unsaturated molecule to make a saturated molecule.
adsorption - Answer-The process that occurs when a gas, liquid or solute is held to
the surface of a solid or, more rarely, a liquid.
alicyclic hydrocarbon - Answer-A hydrocarbon with carbon atoms joined together
in a ring structure.
aliphatic hydrocarbon - Answer-A hydrocarbon with carbon atoms joined together
in straight or branched chains.
alkali - Answer-A type of base that dissolves in water forming hydroxide ions, OH-
(aq) ions.
alkanes - Answer-The homologous series with the general formula: CnH2n+2.
acid - Answer-A species that is a proton donor.
activation energy - Answer-The minimum amount of kinetic energy that particles
need to have in order to react when they collide
addition polymer - Answer-A very long molecular chain formed by repeated
addition reactions of many unsaturated alkene molecules (monomers).
addition polymerisation - Answer-The process in which unsaturated alkene
molecules (monomers) add on to a growing polymer chain one at a time to form a
very long saturated molecular chain (the addition polymer).
addition reaction - Answer-A reaction in which a reactant is added to an
unsaturated molecule to make a saturated molecule.
adsorption - Answer-The process that occurs when a gas, liquid or solute is held to
the surface of a solid or, more rarely, a liquid.
alicyclic hydrocarbon - Answer-A hydrocarbon with carbon atoms joined together
in a ring structure.
aliphatic hydrocarbon - Answer-A hydrocarbon with carbon atoms joined together
in straight or branched chains.
alkali - Answer-A type of base that dissolves in water forming hydroxide ions, OH-
(aq) ions.
,alkanes - Answer-The homologous series with the general formula: CnH2n+2.
alkyl group - Answer-An alkane with a hydrogen atom removed, e.g. CH3, C2H5;
alkyl groups are often shown as 'R'.
amount of substance - Answer-The quantity whose unit of the mole. Chemists use
'amount of substance' as a means of counting atoms.
anhydrous - Answer-A substance that contains no water molecules.
anion - Answer-A negatively charged ion.
atom economy - Answer-atom economy = molecular mass of the desired product
×100 sum of molecular masses of all products
atomic orbital - Answer-A region within an atom that can hold up to two
electrons, with opposite spins.
atomic (proton) number - Answer-The number of protons in the nucleus of an
atom
acid - Answer-A species that is a proton donor.
activation energy - Answer-The minimum energy required to start a reaction by
the breaking of bonds.
, addition polymer - Answer-A very long molecular chain formed by repeated
addition reactions of many unsaturated alkene molecules (monomers).
addition polymerisation - Answer-The process in which unsaturated alkene
molecules (monomers) add on to a growing polymer chain one at a time to form a
very long saturated molecular chain (the addition polymer).
addition reaction - Answer-A reaction in which a reactant is added to an
unsaturated molecule to make a saturated molecule.
adsorption - Answer-The process that occurs when a gas, liquid or solute is held to
the surface of a solid or, more rarely, a liquid.
alicyclic hydrocarbon - Answer-A hydrocarbon with carbon atoms joined together
in a ring structure.
aliphatic hydrocarbon - Answer-A hydrocarbon with carbon atoms joined together
in straight or branched chains.
alkali - Answer-A type of base that dissolves in water forming hydroxide ions, OH-
(aq) ions.
alkanes - Answer-The homologous series with the general formula: CnH2n+2.
