Q8.
A
[1]
Q9.
(a) Covalent
Do not allow dative covalent or coordinate (covalent)
1
(b) Cl(-) not donating lone pair (to Cu(2+))
Cl(-) does not form a coordinate/dative bond (to Cu(2+))
Allow without charges but penalise incorrect charges
Cl−/it is bonded ionically (to Cu2+)
1
(c) [Cu(H2O)6 ]2+ + 4NH3 → [Cu(NH3)4(H2O)2 ]2+ + 4H2O
1
Deep blue / Royal blue / Dark blue (solution)
1
Allow combination of:
[Cu(H2O)6 ]2+ + 2NH3 → [Cu(H2O)4(OH)2 ] + 2NH4+
[Cu(H2O)4(OH)2 ]+ 4NH3 → [Cu(NH3)4(H2O)2 ]2+ + 2H2O + 2OH−
Do not penalise missing square brackets
Ignore initial colour of Cu2+ (aq)
(d) CuCO3 or copper carbonate
Penalise incorrect oxidation state
Allow correct formula for basic copper carbonate
1
(e) HCl/ hydrochloric acid
Ignore concentration
Allow soluble chloride salt
Also allow any reagent which leads to a change in colour of solution due to a change in ligands (e.g. NH2CH2CH2NH2) or change in oxidation state (e.g. SO2 ) and associated correct equations.
1
[Cu(H2O)6 ]2+ + 4Cl− → [CuCl4]2− + 6H2O
[Cu(H2O)6 ]2+ + 4HCl → [CuCl4]2− + 6H2O + 4H+
Mark independently
1
(f) (3)d10 or has full (3)d (sub) shell/orbital
Penalise incorrect principal quantum number
1
It is colourless/cannot absorb (frequencies of) visible light
Ignore clear
1
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