Which of the following does not exist?
KI + I2 → KI3
KF + F2 → KF3
KBr + ICI2 → K[BrICl]
KF + BrF3 → K[BrF4]
Which of the following does not represent the correct order of the property indicated?
Sc3+ > Cr3+ > Fe3+ >Mn3+ - ionic radii
Sc < Ti < Cr < Mn - density
Mn2+ >Ni2+ > Co2+ <Fe2+ - ionic radii
FeO < CaO < MnO < CuO - basic nature
Which of the following oxidation states is the most common among the lanthanoids?
4
2
3
5
C.
3
The most common oxidation state exhibited by lanthanoids is +3.
(The most common and stable oxidation state of Lanthanides is +3.It is attained by removing outermost 2 electrons of 6s electrons and 1 electron from 4f electrons. It is due to high energy difference in 4f and 6s, it is difficult to remove more electrons from 4f sub-shell).
7.5% Ag and 92.5% Cu
92.5% Ag and 7.5% Cu
80% Ag and 20% Cu
90% Ag and 10% Cu
Assertion (A): Cu2+ and Cd2+ are separated by first adding KCN solution and then passing H-S gas.
Reason (R): KCN reduces Cu2+ to Cu+ and forms a complex with it.
The correct answer is
Both (A) and (R) are true and (R) is the correct explanation of (A)
Both (A) and (R) are true but (R) is not the correct explanation of (A)
(A) is true but (R) is not true
(A) is not true but (R) is true
The correct formula of the complex tetraammineaquachlorocobalt (III) chloride is
[Cl(H2O)(NH3)4Co]Cl
[CoCl(H2O)(NH3)4]Cl
[Co(NH3)4(H2O)Cl]Cl
[CoCl(H2O)(NH3)4]Cl2
Across the lanthanide series, the basicity of the lanthanide hydroxides
increases
decreases
first increases and then decreases
first decreases and then increases