The magnetic nature of elements depends on the presence of unpaired electrons. Identify the configuration of transition elements which shows highest magnetic moment?
3d7
3d8
3d5
3d2
Which of the following statement is wrong regarding lanthanoids?
Ln(III) compounds are predominantly ionic in character.
Ln(III) compound are generally colourless
Ln(III) hydroxide are mainly basic in nature
The ionic size of Ln(III) ions decreses with increasing atomic number.
For d block elements the first ionization potential is of the order :
Zn > Fe > Cu > Cr
Sc = Ti < V = Cr
Zn < Cu < Ni < Co
V > Cr > Mn > Fe
The lanthanide contraction is responsible for the fact that
Zr and Zn have the same oxidation state
Zr and Hf have about the same radius
Zr and Nb have similar oxidation state
Zr and Y have about the same radius
The correct order of ionic radii of Y3+, La3+, Eu3+ and Lu3+ is
(Atomic no. Y = 39, La = 57, Eu = 63, Lu = 71)
Lu3+ < Eu3+ < La3+ < Y3+
La3+ < Eu3+ < Lu3+ < Y3+
Y3+ < La3+ < Eu3+ < Lu3+
Y3+ < Lu3+ < Eu3+ < La3+
D.
Y3+ < Lu3+ < Eu3+ < La3+
The correct order of ionic radii is-
Y3+ < Lu3+ < Eu3+ < La3+
because Eu and Lu are the members of lanthanide series (so they show lanthanide contraction) and La is the representative element of all elements of such series and Y3+ ion has lower radii as comparison to La3+ because it lies immediately above it in periodic table.
When copper sulphate solution is added to potassium ferrocyanide, the formula of product obtained is
Cu2Fe(CN)6
Cu(CN)3
CuFe(CN)6
Cu(CN)2
Formation of coloured ions by transition metals signifies;
absorption of light from UV range
emission of light
presence of unparied electrons in s and p orbitals
complimentary colours to the absorbed light