CBSE Questions for Class 12 Engineering Chemistry The D-And F-Block Elements Quiz 5 - MCQExams.com

The aqueous solution of the following salts will be colored in the case of _________.
  • $$Zn(NO_{3})_{2}$$
  • $$LiNO_{3}$$
  • $$Co(NO_{3})_{2}$$
  • $$CrCl_{3}$$
The correct order of unpaired electrons present in d orbitals for elements $$Fe,\ Ti,\ Cr$$ and $$Co$$ is :
  • $$Cr=Fe>Co>Ti$$
  • $$Fe>Co>Cr>Ti$$
  • $$Cr>Fe>Co>Ti$$
  • $$Cr=Fe>Ti>Co$$
Statement 1: Lanthanides have much less tendency to form complexes than actinides.
Statement 2: Compared to actinides, the lanthanides have relatively larger size of atoms and less nuclear charge.
  • Statement 1 is True, statement 2 is True, statement 2 is a correct explanation of statement 1
  • Statement 1 is True, statement 2 is True, statement 2 is not a correct explanation of statement 1
  • Statement 1 is true, Statement 2 is False
  • Statement 1 is False, Statement 2 is True

The magnetic moment of an ion is close to $$36\times 10^{-24}$$Joule /Tesla. The number of unpaired electrons of the ion are ____________.
  • 4
  • 2
  • 1
  • 3

The radius of $$La^{3+}$$ (At. No. of La = 57) is 1.06 A$$^{0}$$. Which one of the following given values will be closest to the radius of $$Lu^{3+}$$?( Atomic number of Lu=71)
  • $$1.40 A^0$$
  • $$1.06 A^0$$
  • $$0.85 A^0$$
  • $$1.60 A^0$$
Which of the following ions will exhibit colour in aqueous solutions?
  • La$$^{3+}$$ (z = 57)
  • Ti$$^{3+}$$ (z = 22)
  • Lu $$^{3+}$$ (z = 71)
  • Sc$$^{3+}$$ (z = 21)
The main reason for larger number of oxidation states exhibited by the actinoids than the corresponding lanthanoids, is:
  • the lesser energy difference between 5f and 6d orbitals than between 4f and 5d orbitals
  • more energy difference between 5f and 6d orbitals than between 4f and 5d orbitals
  • greater reactive nature of the actinoids than the lanthanoids
  • larger atomic size of actinoids than the lanthanoids
In which of the following pairs are both the ions coloured in aqueous solution?
[At. No. : $$Sc = 21, Ti = 22, Ni = 28, Cu = 29, Co = 27$$]
  • $$Ni^{2+}, Ti^{3+}$$
  • $$Sc^{3+}, Ti^{3+}$$
  • $$Sc^{3+}, Co^{2+}$$
  • $$Ni^{2+}, Cu^{+}$$
Out of $$TiF^{2-}_6$$ and $$CoF^{3-}_6$$ , $$Cu_2Cl_2$$ and $$NiCl^{2-}_4$$ (Z of Ti = 22, Co = 27, Cu = 29, Ni = 28) the colourless species are:
  • $$CoF^{3-}_6\; and \;NiCl^{2-}_4$$
  • $$TiF^{2-}_6 \; and \;CoF^{3-}_6$$
  • $$Cu_2Cl_2 \; and \;NiCl^{2-}_4$$
  • $$TiF^{2-}_6 \; and \;Cu_2Cl_2$$
Which one of the following ions is the most stable in aqueous solution?
(At. No. are: $$ Ti = 22, V = 23, Cr = 24, Mn = 25$$)
  • $$Mn^{3+}$$
  • $$Cr^{3+}$$
  • $$V^{3+}$$
  • $$Ti^{3+}$$
Which one of the following ions will be colourless in an aqueous solution?
  • $$Fe^{2+}$$
  • $$Mn^{2+}$$
  • $$Ti^{3+}$$
  • $$Sc^{3+}$$
The catalytic activity of transition metals and their compounds is ascribed mainly to:
  • their unfilled d-orbitals
  • their ability of adopt variable oxidation states
  • their chemical reactivity
  • their magnetic behaviour
The number of oxidation states is exhibited by the actinoids more than by the lanthanide. The main reason for this is:
  • more energy difference between 5f and 6d orbitals than that between 4f and 5d orbitals.
  • the lesser energy difference between 5f and 6d orbitals than between 4f and 5d orbitals.
  • the greater metallic character of the lanthanoids than that of the corresponding actinoids.
  • more active nature of the actinoids.
Which of the following statement is not correct?
  • $$La(OH)_3$$ is less basic than $$Lu(OH)_3$$
  • In Lanthanide series ionic radius of $$Ln^{+3}$$ ions decreases
  • La is actually an element of transition series rather Lanthanide
  • Aomic radius of Zr and Hf are same because of Lanthanide contraction
Which shows maximum magnetic moment among the bivalent ions of the first transition series ?
  • $$Fe^{2+}$$
  • $$Co^{2+}$$
  • $$Ni^{2+}$$
  • $$Mn^{2+}$$

The increasing order of paramagnetism of the following compound is:

(I)$$MnSO_{4}.4H_{2}O  $$

(II)$$FeSO_{4}.7H_{2}O $$

(III)$$   NiSO_{4}.6H_{2}O$$

(IV)$$CuSO_{4}.5H_{2}O$$
  • I < II < III < IV
  •  IV < III < II < I
  • III < IV < II < I
  • III < IV < I < II
The transition metals are mostly :
  • diamagnetic
  • paramagnetic
  • neither diamagnetic nor paramagnetic
  • both diamagnetic and paramagnetic
Salt of which of the elements are mostly blue in colour ?
  • Cu
  • Zn
  • Fe
  • Cr
Which of the following shows highest magnetic moment ?
  • $$Co^{+3}$$
  • $$Cr^{+3}$$
  • $$Fe^{+3}$$
  • $$Ni^{+2}$$
Variable valency is characteristic of:
  • halogen
  • transition elements
  • alkali metals
  • noble gas
Colour of $$Fe^{2+}$$ ions is:
  • blue
  • light green
  • very dark green
  • yellow
Of the following metals, the most reactive metal is:
  • $$Fe$$
  • $$Ni$$
  • $$Pt$$
  • $$Au$$
Ammonium dichromate on heating gives:
  • chromic oxide and nitrogen
  • chromic acid and ammonia
  • chromic acid and nitrogen
  • chromic oxide and ammonia
A compound of vanadium possesses a magnetic moment of 1.73 BM. The oxidation state of vanadium in this compounds is :
  • 1
  • 2
  • 4
  • can not be predicted.
The ionic radius of $$_{57}La^{3+}$$ is 1.06 A. Which one of the following given values will be closest to the ionic radius of $$_{71}Lu^{3+}?$$
  • 1.06 A
  • 1.56 A
  • 0.85 A
  • 1.35 A
Which of the following does not corrode when exposed to the atmosphere?
  • iron
  • copper
  • gold
  • silver
  • Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
  • Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
  • Assertion is correct but Reason is incorrect
  • Assertion is incorrect but Reason is correct
Which of the following ion involved in the above process will show paramagnetism?
  • $${ V }^{ 5+ }$$
  • $${ V }^{ 4+ }$$
  • $${ O }^{ 2- }$$
  • $${ VO }_{ 3 }^{ - }$$
Knowing that the chemistry of lanthanids (Ln) is dominated by its +3 oxidation state, which of the following statements are correct?
(I)  The ionic sized of Ln (III) decreases in general with increasing atomic number.
(II)  Ln (III) compounds are generally colourless.
(III)  Ln (III) hydroxides are mainly basic in character.
(IV)  Because of the large size of the Ln (III) ions, the bonding in its compounds is predominently ionic in character.
  • I, III and III
  • II, III and IV
  • I, II and IV
  • I, III and IV
Lanthanide contraction implies:
  • decrease in density
  • decrease in mass
  • decrease in ionic radii
  • decrease in radioactivity
Which of the following elements is placed just after actinide series?
  • Rutherfordium
  • Unnilpentium
  • Unnilquadium
  • Ununbium
All $$Zn(+II)$$ compounds are white because:
  • $${ Zn }^{ 2+ }$$ has a $${d}^{10}$$ configuration and the $$d$$-subshell is full
  • $${ Zn }^{ 2+ }$$ shows $$d-d$$ transition
  • $${ Zn }^{ 2+ }$$ has no electron in the $$4s-$$subshell
  • $$Zn$$ is not a transition element
Which of the following factors favour the formation of complexes by d-block elements?
  • Small size.
  • High nuclear charge.
  • Presence of low energy vacant orbitals to accept lone pair of electrons donated by ligands.
  • All of the above
To protect iron against corrosion, the most durable metal plating on it, is :
  • nickel plating
  • tin plating
  • copper plating
  • zinc plating
The main reason for larger number of oxidation state exhibited by the actinides than that corresponding lanthanide, 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 differenc between 5f and 6d orbitals than between 4f and 5d-orbitals
  • greater reactive nature of the actinides than the lanthanides
Misch metal is:
  • an alloy of lathanide and copper
  • an alloy of lanthanide and nickel
  • an alloy of lathanide,iron and carbon
  • an alloy of calcium and copper
The atomic radii of cerium and promethium are quite similar because
  • they belong to the same period in periodic table
  • they have similar electronic configuration
  • f-orbitals have poor shielding effect
  • nuclear charge is higher on cerium than promethium
The transition metal used as a catalyst is :
  • nickel
  • platinum
  • cobalt
  • all of these
The magnetic moment order is correctly given in:
  • $$Fe^{2+} < Fe^{3+} < Mn^{4+} < Cr^{3+}$$
  • $$Cr^{3+} = Mn^{4+} < Fe^{2+} < Fe^{3+}$$
  • $$Cr^{3+} = Mn^{4+} < Fe^{3+} < Fe^{2+}$$
  • $$Fe^{2+} < Cr^{3+} < Fe^{3+} < Mn^{4+}$$
$$Fe$$ is made passive by:
  • $$dil.\ H_2SO_4$$
  • $$dil.\ HCl$$
  • $$conc. \ HNO_3$$
  • $$conc.\ H_2SO_4$$
The highest magnetic moment is shown by
  • $$Ni$$
  • $$Co$$
  • $$Fe$$
  • $$Sc$$
Which of the following is not an actinide ?
  • Curium
  • Californium
  • Uranium
  • Terbium
Which plays a major role in the formation of complex compound ?
  • Transition metal
  • Lanthanides and actinides
  • Representative elements
  • p-block element
Which of the following lanthanide is commonly used ?
  • Lanthanium
  • Nobelium
  • Thorium
  • Cerium
Transition elements does not show :
  • paramagnetism
  • colour
  • fixed valency
  • all of these
Which of the following electronic configuration will be associated with the lowest magnetic moment?
  • $${ d }^{ 2 }$$
  • $${ d }^{ 3 }$$
  • $${ d }^{ 4 }$$
  • $${ d }^{ 9 }$$
The magnetic moment of a transition metal of $$3d$$-series is $$6.92BM$$. Its electronic configuration will be:
  • $${ \left( 3d \right) }^{ 4 }{ \left( 4s \right) }^{ 2 }$$
  • $${ \left( 3d \right) }^{ 5 }{ \left( 4s \right) }^{ 1 }$$
  • $${ \left( 3d \right) }^{ 10 }$$
  • $${ \left( 3d \right) }^{ 5 }{ \left( 4s \right) }^{ 0 }$$
$$\displaystyle [{ Fe\left( { H }_{ 2 }{ O } \right)  }_{ 5 }{ No{ ] }^{ 2+ } }$$ is formed as brown ring in $$\displaystyle { NO }_{ 3 }^{ + }$$ test. $$\displaystyle Fe$$ in this complex has _________ unpaired electrons.
  • one
  • two
  • three
  • four
Arrange the following ions in order of their magnetic moment:

$$(i) {V}^{4+}$$ $$(ii) {Mn}^{4+}$$ $$(iii) {Fe}^{3+}$$ $$(iv){Ni}^{2+}$$

[Atomic number of $$V=23, Mn=25,Fe=26,Ni=28$$]
  • $$(ii)> (iii)> (i)> (iv)$$
  • $$(iii)> (ii)> (iv)> (i)$$
  • $$(i)> (iv)> (iii)> (ii)$$
  • $$(iv)> (iii)> (i)> (ii)$$
The position in the periodic table to which the $$Al$$ metal belongs : 
  • Alkali metals
  • Alkaline earth metals
  • $$d$$ - block elements
  •  $$p$$ - block elements
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