Multiple Choice QuestionsA metal has a fcc lattice. The edge length of the unit cell is 404 pm. The density of the metal is 2.72 g cm-3. The molar mass of the metal is (NA Avogadro's constant= 6.02 x 1023 mol-1)
40 g mol-1
30 g mol-1
27 g mol-1
27 g mol-1
A magnetic moment of 1.73 BM will be shown by one among the following
[Cu(NH3)4]2+
[Ni(CN)4]2-
TiCl4
TiCl4
Roasting of sulphides gives the gas X as a by-product. This is a colourless gas with the choking smell of burnt sulphur and causes great damage to respiratory organs as a result of acid rain. Its aqueous solution is acidic acts as a reducing agent and its acid has never been isolated. The gas X is
H2S
SO2
CO2
CO2
Which of the following does not give oxygen on heating?
KClO3
Zn(ClO3)2
K2Cr2O7
K2Cr2O7
Which of the following lanthanoid ions is diamagnetic?
(At. number; Ce =58, Sm =62, Eu =63, Yb = 70)
Ce2+
Sm2+
Eu2+
Eu2+
D.
Eu2+
Lanthanoid ion with no unpaired electron is diamagnetic in nature.
Ce58 = [Xe]4f2 5d0 6s2
Ce2+ = [Xe]4f2 (two unpaired electrons)
Sm62 = [Xe]4f6 5d0 6s2
Sm2+ = [Xe] 4f6 (six unpaired electron)
Eu63 = [Xe]4f7 5d0 6s2
Eu2+ = [Xe] 4f7 (seven unpaired electron)
Yb70 = [Xe]4f14 5d0 6s2
Yb2+ = [Xe] 4f14 (No unpaired electron)
Because of the absence of unpaired electrons, Yb2+ is diamagnetic.
Identify the correct order of solubility in aqueous medium
CuS> ZnS> Na2S
ZnS > Na2S> CuS
Na2S> CuS> ZnS
Na2S> CuS> ZnS
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