CHEMISTRY AQA PAPER 2 MARKING SCHEME 2020
Mass number - (answer)Total number of protons and neutrons.
Atomic number - (answer)Numbers of protons in the nucleus and number of electrons in shells.
Negative Ions - (answer)More electrons than protons.
Positive ions - (answer)More protons than electrons.
Relative isotopic mass - (answer)mass of an atom of an isotope of an element on a scale where an atom
of carbon12 is 12.
Relative atomic mass - (answer)average mass of an atom of an element on a scale where an atom of
carbon12 is 12.
Relative molecular mass - (answer)average mass of a molecule on a scale where an atom of carbon12 is
12.
First ionisation energy - (answer)the energy needed too remove 1 electron from each atom in 1 mole of
gaseous atoms to form 1 mole of gaseous 1+ ions.
Second ionisation energy - (answer)the energy needed to remove 1 electron from each ion in 1 mole of
gaseous 1+ ions to form 1 mole of gaseous 2+ ions.
Number of particles= - (answer)Number of moles x Avagadros constant (6.02 x 10^23)
Number of moles= - (answer)Mass / Mr
Number of moles= - (answer)Concentration (moldm^-3) x Volume (dm^3)
, Methyl orange indicator - (answer)yellow in acid, red in alkali. Commonly used in titrations.
Phenolphthalein indicator - (answer)pink in alkali, colourless in acid. Commonly used in titrations.
Avogadros constant - (answer)the number of atoms in 12g of carbon12 (6.02 x 10^23)
Ideal gas equation - (answer)Pv= nRT
Empirical formula - (answer)simplest whole number ratio of atoms of each element in a compound.
Molecular formula - (answer)gives the actual numbers of each element in a molecule.
Percentage yield - (answer)how much product was actually made compared with the amount of product
that was expected
theoretical yield - (answer)the maximum mass of product expected in a reaction.
actual yield - (answer)the mass of product that is actually obtained in a reaction.
Atom economy - (answer)measure of the efficiency of a chemical reaction. The proportional mass of
reactants that actually become part of the desired product in a balanced chemical equation.
Ionic bonding - (answer)Ions (metal and non metal) are held together by electrostatic forces of attraction
due to the transferring of electrons. Eg: Sodium chloride.
Mass spectrometer - (answer)An instrument used to accurately determine the relative atomic mass.
Separates atoms or molecules (gaseous positive ions) according to their charge and mass.
Orbital - (answer)Region in space where one is likely to find up to two electrons with opposite spin.
Mass number - (answer)Total number of protons and neutrons.
Atomic number - (answer)Numbers of protons in the nucleus and number of electrons in shells.
Negative Ions - (answer)More electrons than protons.
Positive ions - (answer)More protons than electrons.
Relative isotopic mass - (answer)mass of an atom of an isotope of an element on a scale where an atom
of carbon12 is 12.
Relative atomic mass - (answer)average mass of an atom of an element on a scale where an atom of
carbon12 is 12.
Relative molecular mass - (answer)average mass of a molecule on a scale where an atom of carbon12 is
12.
First ionisation energy - (answer)the energy needed too remove 1 electron from each atom in 1 mole of
gaseous atoms to form 1 mole of gaseous 1+ ions.
Second ionisation energy - (answer)the energy needed to remove 1 electron from each ion in 1 mole of
gaseous 1+ ions to form 1 mole of gaseous 2+ ions.
Number of particles= - (answer)Number of moles x Avagadros constant (6.02 x 10^23)
Number of moles= - (answer)Mass / Mr
Number of moles= - (answer)Concentration (moldm^-3) x Volume (dm^3)
, Methyl orange indicator - (answer)yellow in acid, red in alkali. Commonly used in titrations.
Phenolphthalein indicator - (answer)pink in alkali, colourless in acid. Commonly used in titrations.
Avogadros constant - (answer)the number of atoms in 12g of carbon12 (6.02 x 10^23)
Ideal gas equation - (answer)Pv= nRT
Empirical formula - (answer)simplest whole number ratio of atoms of each element in a compound.
Molecular formula - (answer)gives the actual numbers of each element in a molecule.
Percentage yield - (answer)how much product was actually made compared with the amount of product
that was expected
theoretical yield - (answer)the maximum mass of product expected in a reaction.
actual yield - (answer)the mass of product that is actually obtained in a reaction.
Atom economy - (answer)measure of the efficiency of a chemical reaction. The proportional mass of
reactants that actually become part of the desired product in a balanced chemical equation.
Ionic bonding - (answer)Ions (metal and non metal) are held together by electrostatic forces of attraction
due to the transferring of electrons. Eg: Sodium chloride.
Mass spectrometer - (answer)An instrument used to accurately determine the relative atomic mass.
Separates atoms or molecules (gaseous positive ions) according to their charge and mass.
Orbital - (answer)Region in space where one is likely to find up to two electrons with opposite spin.
