AQA Chemistry A level Questions and
Answers 100% Solved
what is a lewis acid electron pair acceptor (metal ion)
what is a lewis base electron pair donor (ligand)
colour of hexaaqua iron (II) green
colour of hexaaqua copper (II) blue
colour of hexaaqua aluminium (III) colourless (not a transition metal)
colour of hexaaqua iron (III) violet
what is a hydrolysis/acidity reaction addition of water/removal of a hydrogen
[M(H2O)6]2+ + H2O --> [M(H2O)5(OH)]+ + H3O+
,why are 3+ ions more acidic than 2+ The acidity of [M(H2O)6]3+ is greater than that of
[M(H2O)6]2+ in terms of the greater polarising power (charge/size ratio) of the 3+ metal ion.
The greater the polarising power, the more strongly it attracts the water molecule. This weakens
the O-H bond so it breaks more easily.
Precipitate of Copper (II) with hydroxide or NH3 (deprotonation acid-base reaction) blue
Precipitate of Iron (II) with hydroxide or NH3 (deprotonation acid-base reaction) green
Precipitate of aluminium (III) with hydroxide or NH3 (deprotonation acid-base reaction)
white
Precipitate of Iron (III) with hydroxide or NH3 (deprotonation acid-base reaction) brown
what happens to Aluminium with excess OH- With excess NaOH the Al hydroxide dissolves.
Al becomes [Al(OH)4]- (aq) colourless solution. This hydroxide is classed as amphoteric
because it reacts and dissolves in both acids and bases.
,what happens to copper with excess ammonia With excess NH3 Cu and its precipitate
dissolve
deep blue solution
reactions of M2+ ions with carbonates form solid carbonate salt precipitates (straight
precipitation reaction)
what happens with M3+ ions with carbonates The 3+ ions with carbonate solution form a
M(OH)3 ppt and CO2 gas is evolved
why is a carbonate salt not formed with metal 3+ ions MCO3 is formed with 2+ ions but
M2(CO3)3 is not formed with 3+ ions. The difference is explained by the greater polarising
power of the 3+ ion due to its higher charge density.
precipitates formed in the carbonate (acidity reactions) Al forms white ppt of Al(OH)3
(H2O)3 + CO2 Fe(III) forms brown ppt of Fe(OH)3 (H2O)3 + CO2
What is the relative mass and charge on a proton? Mass 1
charge +1
, What is the relative mass and charge on a neutron? Mass 1
Charge 0
What is the relative mass and charge on an electron? Mass 1/2000
Charge -1
What is the mass number? The total number of protons and neutrons in the nucleus of an
atom
What is the Atomic (proton) number? This is the number of protons in the nucleus of an atom
and is used to identify an element
What are Ions? Ion have different numbers of protons and electrons. Negative ions have more
electrons than protons and positive ions have fewer electrons than protons.
What are isotopes? Isotopes of an element are atoms with the same number of protons but
different numbers of neutrons
Answers 100% Solved
what is a lewis acid electron pair acceptor (metal ion)
what is a lewis base electron pair donor (ligand)
colour of hexaaqua iron (II) green
colour of hexaaqua copper (II) blue
colour of hexaaqua aluminium (III) colourless (not a transition metal)
colour of hexaaqua iron (III) violet
what is a hydrolysis/acidity reaction addition of water/removal of a hydrogen
[M(H2O)6]2+ + H2O --> [M(H2O)5(OH)]+ + H3O+
,why are 3+ ions more acidic than 2+ The acidity of [M(H2O)6]3+ is greater than that of
[M(H2O)6]2+ in terms of the greater polarising power (charge/size ratio) of the 3+ metal ion.
The greater the polarising power, the more strongly it attracts the water molecule. This weakens
the O-H bond so it breaks more easily.
Precipitate of Copper (II) with hydroxide or NH3 (deprotonation acid-base reaction) blue
Precipitate of Iron (II) with hydroxide or NH3 (deprotonation acid-base reaction) green
Precipitate of aluminium (III) with hydroxide or NH3 (deprotonation acid-base reaction)
white
Precipitate of Iron (III) with hydroxide or NH3 (deprotonation acid-base reaction) brown
what happens to Aluminium with excess OH- With excess NaOH the Al hydroxide dissolves.
Al becomes [Al(OH)4]- (aq) colourless solution. This hydroxide is classed as amphoteric
because it reacts and dissolves in both acids and bases.
,what happens to copper with excess ammonia With excess NH3 Cu and its precipitate
dissolve
deep blue solution
reactions of M2+ ions with carbonates form solid carbonate salt precipitates (straight
precipitation reaction)
what happens with M3+ ions with carbonates The 3+ ions with carbonate solution form a
M(OH)3 ppt and CO2 gas is evolved
why is a carbonate salt not formed with metal 3+ ions MCO3 is formed with 2+ ions but
M2(CO3)3 is not formed with 3+ ions. The difference is explained by the greater polarising
power of the 3+ ion due to its higher charge density.
precipitates formed in the carbonate (acidity reactions) Al forms white ppt of Al(OH)3
(H2O)3 + CO2 Fe(III) forms brown ppt of Fe(OH)3 (H2O)3 + CO2
What is the relative mass and charge on a proton? Mass 1
charge +1
, What is the relative mass and charge on a neutron? Mass 1
Charge 0
What is the relative mass and charge on an electron? Mass 1/2000
Charge -1
What is the mass number? The total number of protons and neutrons in the nucleus of an
atom
What is the Atomic (proton) number? This is the number of protons in the nucleus of an atom
and is used to identify an element
What are Ions? Ion have different numbers of protons and electrons. Negative ions have more
electrons than protons and positive ions have fewer electrons than protons.
What are isotopes? Isotopes of an element are atoms with the same number of protons but
different numbers of neutrons
