Which of the following statements regarding Lanthanides is false?
All lanthanides are solid at room temperature
Their usual oxidation state is +3
They can be separated from one another by ion-exchange method
Ionic radii of trivalent lanthanides steadily increases with increase in atomic number
The correct basicity order of the following lanthanide ions is
La3+ > Lu3 > Ce3+ > Eu3+
Ce3+ > Lu3+ > La3+ > Eu3+
Lu3+ > Ce3+ > Eu3+ > La3+
La3+ > Ce3+ > Eu3+ > Lu3+
Extraction of gold (Au) involves the formation of complex ions X and Y.
Gold ore HO- + X Y + Au
X and Y respectively are
Au(CN) and Zn(CN)
Au(CN) and Zn(CN)
Au(CN) and Zn(CN)
Au(CN) and Zn(CN)
The atomic number of cerium (Ce) is 58. The correct electronic configuration of Ce3+ ion is
[Xe]4f1
[Kr]4f1
[Xe]4f13
[Kr]4d1
Cold ferrous sulphate solution on absorption of NO develops brown colour due to the formation of
paramagnetic [Fe(H2O)5(NO)]SO4
dimagnetic [Fe(H2O)5(NO)]SO4
paramagnetic [Fe(H2O)5(NO3)][SO4]2
diamagnetic [Fe(H2O)4(SO4)]NO3
Roasted copper pyrite on smelting with sand produces
FeSiO3 as fusible slag and Cu2S as matte
CaSiO3 as infusible slag and Cu2O as matte
Ca3(PO4)2 as fusible slag and Cu2S as matte
Fe3(PO4)2 as infusible slag and Cu2S as matte
Cupric compounds are more stable than their cuprous counterparts in solid state. This is because
the endothermic character of the 2nd IP of Cu is not so high
size of Cu+ is less than Cu2+
Cu2+ has stabler electronic configuration as compared to Cu+
the lattice energy released for cupric compounds
is much higher than Cu+
A.
the endothermic character of the 2nd IP of Cu is not so high
B.
size of Cu+ is less than Cu2+
D.
the lattice energy released for cupric compounds
is much higher than Cu+
Electronic configurations of cuprous (Cu+) and cupric (Cu2+) ions are as follows
Cu+ = [Ar] 3d10 4s0
Cu2+= [Ar] 3d9 4s0
Thus, electronic configuration of cut is more stable but it is less stable because in Cu+ due to its small size the nuclear charge is sufficient to hold 27 electrons but in Cu2+ such a condition is not true.
Further, the IInd IP of Cu is not very high as compared to its Ist IP. Consequently a large amount of lattice energy is released for cupric compounds as compared to Cu+ compounds.
Li occupies higher position in the electrochemical series of metals as compared to Cu since
the standard reduction potential of Li+/Li is lower than that of Cu2+ /Cu
the standard reduction potential of Cu2+/Cu is lower than that of Li+/Li
the standard oxidation potential of Li/Li+ is lower than that of Cu/Cu2+
Li is smaller in size as compared to Cu
The equivalent weight of K2Cr2O7 in acidic medium is expressed in terms of its molecular weight (M) as
M/3
M/4
M/6
M/7