a level chemistry inorganic paper
ionic equation to form E
2Ag+ + CO3 2- --> Ag2CO3
give an equation and two observations when Na is heated in O2
4Na + O2 --> 2Na2O orange flame, white solid
give an equation and one observation when P is heated in O2
4P + 5O2 --> P4O10 white flame
what is the formula of the salt which gives a white precipitate when added to silver nitrate?
A - BaCl2
which will not act as a ligand in the formation of a complex ion?
A - CH4
formula of E
Ag2CO3
formula of D
AgBr
conversion of D into G
AgBr + 2NH3 --> [Ag(NH3)2]+ + Br-
give the formula of white precipitate B
Al(H2O)3(OH)3
which shows the electron configuration of an atom of a transition metal?
B - [Ar] 4s2 3d8
what is observed when Ba is added to water?
B - forms a colourless solution and effervesces
Why is HNO3 used when testing for halides?
B - it prevents the precipitation of silver ions other than halides
what is the minimum volume of 0.02 mol dm-3 KMnO4 solution needed to oxidise 0.1 mol of VO2+?
C - 100
which compound decolourises acidified potassium permanganate?
C - FeSO4
formula of F
CO2
which shows the correct oxidation state and coordination number of cobalt in [Co(NH3)5Cl]Cl2?
D - oxidation state 3+, co-ordination number 6
what happens when HCl is added to CuSO4?
D - the solution changes colour and no precipitate forms
explain the increase in melting point from Na2O to MgO
Mg 2+ is smaller and has higher charge density so stronger attraction between Mg 2+ and O2- ions
give the formula of complex ion C
[Al(OH)6]3-
deduce the formula of the complex ion A
[AlEDTA]-
state the meaning of the term heterogenous catalyst
a catalyst which is in a different physical state to the products and reactants
state one other observation when Na2CO3 is added to [Al(H2O)6]3+ ions and give an equation
effervescence 2(Al(H2O)6)3+ + 3Na2CO3 → 2Al(H2O)3(OH)3 + 3CO2 + 6Na + 3H2O
state one condition needed for the formation of C from [Al(H2O)6]3+ and NaOH and give an equation
excess NaOH [Al(H2O)6]3+ + 6NaOH --> [Al(OH)6]3- + 6H2O + 6Na
explain why atomic radius decreases from Na to Cl
nuclear charge increases while shielding is the same
calculate the energy given by each excited electron
ΔE = hν = hC/ λ ΔE = 6.63 x 10^-34 x (3 x 10^8/490 x 10^-9) = 4.06 x 10^-19
explain, with the use of an equation, why a solution containing [Al(H2O)6]3+ has a pH <7
• Al has a high charge density which increases O-H polarity • the H atoms are δ+ enough to get removed in addition of water [Al(H2O)6]3+ --> [Al(H2O)5(OH)]2+ + H+
explain why Si has a higher melting point than P4O10
• Si2O is giant covalent, P4O10 is simple molecular • Si2O has stronger covalent bonds, P4O10 has weaker vdW
explain why complexes formed from transition metals are coloured
• incomplete d subshell • some wavelengths are absorbed, some are reflected • light excites d electrons and raises them from ground state
describe how a calibration graph is produced and used to find the concentration of the iron iii complex
• measures absorption of visible radiation • plot absorption against known concentrations of solution • use graph to find unknown