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