In which of the following compounds transition metal has zero oxidation state ?
[Fe(CO)5]
NH2 . NH2
NOClO4
CrO5
Copper sulphate dissolves in excess of KCN to give
CuCN
[Cu(CN)4]3-
[Cu(CN)4]2-
Cu(CN)2
CuSO4 when reacts with KCN forms CuCN, which is insoluble in water. It is soluble in excess of KCN, due to formation of the following complex
K2[Cu(CN)4]
K3[Cu(CN)4]
Cu[K Cu(CN)4]
The main reason for larger number of oxidation states exhibited by the actinides than the corresponding lanthanides, is
lesser energy difference between 5f and 6d orbitals than between 4f and 5d orbitals
larger atomic size of actinides than the lanthanides
more energy difference between 5f and 6d orbitals than between 4f and 5d orbitals
greater reactive nature of the actinide than the lanthanides
The transition elements have a general electronic configuration
ns2np6nd1-10
(n-1)d1-10, ns0-2, np0-6
(n-1)d1-10, ns1-2
nd1-10ns2
Cuprous compounds such as CuCl, CuCN and CuSCN are the only salts stable in H2O due to
high hydration energy of Cu+ ions
their inherent tendency not to disproportionate
diamagnetic nature
insolubility in water
When (NH4)2Cr2O7 is heated, the gas evolved is
N2
NO2
O2
N2O
Which of the following statements is not correct ?
La(OH)3 is less basic than Li(OH)3
In lanthanide series ionic radius of Ln3- ion decreases.
La is actually an element of transition series rather lanthanide
Atomic radius of Zr and Hf are same because of lanthanide contraction