A LEVEL CHEMISTRY OCR A UPDATED
ACTUAL QUESTIONS AND CORRECT
ANSWERS COMPLETE STUDY GUIDE
●● 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.
ACTUAL QUESTIONS AND CORRECT
ANSWERS COMPLETE STUDY GUIDE
●● 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.
