CBSE Questions for Class 12 Engineering Chemistry The D-And F-Block Elements Quiz 4 - MCQExams.com

Zinc chromate and lead chromate are used as:
  • lakes
  • lacquers
  • mordants
  • pigments
The correct statement for d-block element is:
  • It shows magnetic property
  • It has variable valency
  • It has tendency of formation of colored ions
  • It has complete d-orbitals
The atomic numbers of elements of second inner transition elements lie in the range of :
  • 88 to 101
  • 89 to 102
  • 90 to 103
  • 91 to 104
The chemical similarity between boron and silicon mainly due to equal value of their:
  • electronegativity
  • nuclear charge
  • charge to (ionic radius)$$^{2}$$ ratio
  • atomic volume
Beryllium resembles Aluminium in properties. This is mainly due to:
  • equal electro negativity values of elements
  • equal atomic volumes of the elements
  • equal electron affinity
  • equal nuclear charges in their atoms
The starting element in the incomplete period of long form of periodic table
  • $$Cs$$
  • $$Rn$$
  • $$Fr$$
  • $$Th$$
Elements which generally exhibit variable oxidation states and form colored ions are ___________.
  • metalloids
  • transition elements
  • non-metals
  • gases
Most of the radio active elements are present in:
  • Lanthanoids
  • Actinoids
  • Representative elements
  • Second transition series
The element californium belongs to a family of :
  • actinide series
  • alkali metal family
  • alkaline earth family
  • lanthanide series
Transition metals are often paramagnetic owing to:
  • high m.p. and b.p. of transition metals
  • presence of vacant d-orbitals
  • presence of one or more unpaired d-electrons
  • their less electropositive nature as compared to the elements of groups IA and IIA
A reduction in atomic size with increase in atomic number is a characteristic of elements of:
  • d-block
  • f-block
  • radioactive series
  • high atomic masses
Lanthanoid contraction occurs because
  • the 4f electrons, which are gradually added, create strong shielding effect
  • the 4f orbitals are greater in size than the 3d and 3f orbitals
  • the 5f orbitals strongly penetrate into the 4f orbitals
  • the poor shielding effect of 4f electrons is coupled with increased attraction between the nucleus and the added electrons
Which of the following has smallest ionic radius ?
  • Lu$$^{3+}$$
  • Nd$$^{3+}$$
  • Dy$$^{3+}$$
  • Pm$$^{3+}$$
The atomic and ionic radii ($$M^{3+}$$ ions) of Lanthanide elements decrease with increase in atomic number. This effect is called as:
  • Lanthanoid contraction
  • Lanthanoid expansion
  • Actinoid contraction
  • none of these
The separation of Lanthanides by ion exchange method is based on:
  • basicity of the hydroxides
  • size of the ions
  • the solubility of their nitrates
  • oxidation state of the ion
Which element among the Lanthanides has the smallest atomic radius ?
  • Cerium
  • Lutetium
  • Europium
  • Gadolinium.
Which of the following belongs to the actinide series of elements?
  • Y
  • Ta
  • U
  • Lu
The radius of $$La^{3+}$$ (At. no. of La = 57) is 1.06A. Which one of the following given values will be closest to the radius of $$Lu^{3+}$$? (At. no. of Lu = 71)
  • 1.40A
  • 1.06A
  • 0.85A
  • 1.60A
The Lanthanoid contraction refers to decrease in the:
  • valence electrons of the Lanthanide series
  • ionic radius of the series
  • the density of the series
  • nuclear mass of the series
Transuranic elements begin with :
  • Np
  • Cm
  • Pu
  • U
Differentiating electron in inner transition elements enters the ________ orbital.
  • s
  • p
  • d
  • f
Many Lanthanoid elements are used to prepare:
  • ceramic materials
  • water softener
  • superconducting materials
  • enzyme catalysts
The correct order of ionic radii of $$Yb^{3+},La^{3+},Eu^{3+}$$ and $$Lu^{3+}$$ is:
  • $$Yb^{3+}> Lu^{3+}> Eu^{3+}> La^{3+}$$
  • $$Lu^{3+}< Yb^{3+}< Eu^{3+}< La^{3+}$$
  • $$Lu^{3+}< Eu^{3+}< La^{3+}< Yb^{3+}$$
  • $$La^{3+}< Eu^{3+}< Lu^{3+}< Yb^{3+}$$

Which of the following statement regarding transition elements is incorrect?
  • Their atoms contain partially filled d orbitals.
  • They are capable of showing variable valencies.
  • All of their ions are colourless.
  • They form complexes readily.

Catalytic activity of transition elements and their compounds is due to their _______.
  • small size
  • vacant d-orbitals
  • higher densities
  • colour
Which has the highest ionic radii among given ions?
 $$Ce^{3+}, La^{3+}, Pm^{3+}$$ and $$Yb^{3+}$$ 
  • $$Yb^{3+}$$
  • $$Ce^{3+}$$
  • $$La^{3+}$$
  • $$Pm^{3+}$$
Which of the following compounds is most widely used as an oxidizing agent in the volumetric analysis?
  • $$CeO_{2}$$
  • $$(NH_{4})_{2}[Ce(NO_{3})_{6}]$$
  • $$Ce(SO_{4})_{2}$$
  • $$CeF_{3}$$

The following belongs to d-block but it is not transition element 
  • Mn
  • Fe
  • Zn
  • Cr

Chemically Zinc group elements closely resemble ______.
  • I A group
  • II A group
  • III A group
  • IV A group

The elements which exhibit both vertical and horizontal similarities are _______.
  • inert gas elements
  • representative elements
  • rare elements
  • transition elements

Which of the following is used as Catalyst in the hydrogenation of oil?
  • $$V_{2}O_{5}$$
  • Pd
  • Fe
  • Ni

d -block elements form complexes because they have:
  • vacant orbitals
  • small sizes
  • higher nuclear charge
  • all of the above
Which of the following is not an interstitial compound?
  • $$TiC$$
  • $$MoC$$
  • $$Fe_{0.82}O$$
  • $$Cr_{2}O_{3}$$

The property seen in f-block elements is :
  • Lanthanoid contraction
  • Actinide contraction
  • both (A) and (B)
  • Lanthanoid expansion

Many lanthanoid elements are used to prepare:
  • ceramic materials
  • water softener
  • superconducting materials
  • enzyme catalysts

Oil is converted into fat by using ____ as a catalyst.
  • Ni
  • Fe
  • Mn
  • $$V_{2}O_{5}$$

Magnetic moment of diamagnetic substance in Bohr Magnetons is:
  • 1.73
  • 2.83
  • 50
  • 0

The atomic and ionic radii (M$$^{3+}$$ ions) of Lanthanide elements decrease with increase in atomic number. This effect is called: 
  • Lanthanoid contraction
  • f-f transition
  • Actinoid contraction
  • shielding effect

The magnetic moment of an ion in its +3 oxidation state is 3.85 BM. The number of unpaired electrons present in the ion is _____________.
  • 1
  • 4
  • 3
  • 5

In dichromate ion ________________________.
  • 4 Cr-O bonds are equivalent
  • 6 Cr-O bonds are equivalent
  • 8 Cr-O bonds are equivalent
  • all Cr-O bonds are equivalent

Arrange $$Ce^{3+}, La^{3+}, Pm^{3+}$$ and $$Yb^{3+}$$ in increasing order of their ionic radii.
  • $$Yb^{3+} < Pm^{3+} < Ce^{3+} < La^{3+}$$
  • $$Ce^{3+} < Yb^{3+} < Pm^{3+} < La^{3+}$$
  • $$Yb^{3+} < Pm^{3+} < La^{3+} < Ce^{3+}$$
  • $$Pm^{3+} < La^{3+} < Ce^{3+} < Yb^{3+}$$

The radius of $$La^{3+}$$ (atomic number of La $$=$$ 57) is 1.06A. Which one of the following given values will be closest to the radius of $$Lu^{3+}$$? (atomic number of Lu=71)
  • 1.40A
  • 1.06A
  • 0.85A
  • 1.60A

Transition elements show positive oxidation state, generally, due to:
  • large atomic size
  • low ionization energy
  • low electronegativity
  • high electronegativity

Which one of the following ion exhibits colour in aqueous solution ?      
  • Sc$$^{3+}$$
  • Ni$$^{2+}$$
  • Ti$$^{4+}$$
  • Zn$$^{+2}$$
Select the correct order with respect to paramagnetic property of the ions.
  • $$Mn^{2{+}} > Cr^{2+} > V^{2{+}} > Ti^{2+}$$
  • $$Ti^{2{+}} > V^{2{+}} > Mn^{2{+}} > Cr^{{2+}}$$
  • $$V^{2{+}} > Ti^{2{+}} > Mn^{2{+}} > Cr^{2{+}}$$
  • $$Ti^{2{+}} > V^{2{+}} > Mn^{2{+}} > Cr^{2{+}}$$

Variable valency of transition elements is on account of :
  • incomplete s - orbitals
  • incomplete d - orbitals
  • completely filled d - orbitals
  • incomplete p-orbitals
Which of the following pair has the same size?
  • Fe$$^{2+}$$, Ni$$^{2+}$$
  • Zr$$^{4+}$$, Ti$$^{4+}$$
  • Zr$$^{4+}$$, Hf$$^{4+}$$
  • Zn$$^{2+}$$, Hf$$^{4+}$$

Colour in transition metal compounds is attributed to :
  • small size of metal ions
  • absorption of light in UV region
  • complete $$(ns)$$ subshell
  • incomplete $$(n-1)d$$ subshell

Transition metals are less reactive because of their :
  • High ionization potential and low melting point
  • High ionization potential and high melting point
  • Low ionization potential and low melting point
  • Low ionization potential and high melting point
Which of the following arrangements does not represent the correct order of the property stated against it? 
  • $$Ni^{2+} < Co^{2+} < Fe^{2+} < Mn^{2+}$$ : Ionic size
  • $$Co^{3+} < Fe^{3+} < Cr^{3+} < Sc^{3+}$$ : Stability in aqueous solution
  • $$Sc < Ti < Cr < Mn $$ : Number of oxidation states
  • $$V^{2+} < Cr^{2+} < Mn^{2+} < Fe^{2+}$$ : Paramagnetic behaviour
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