CBSE Questions for Class 12 Engineering Chemistry The D-And F-Block Elements Quiz 1 - MCQExams.com

The ionic charges on chromate ion and dichromate ion respectively is:
  • $$-2, -2$$
  • $$-3, -2$$
  • $$-2, -4$$
  • $$-4, -2$$
Which element is a transition metal?
  • melting point in $$^{o}C$$ - 98; density in $$g/{cm}^{3}$$- 1.0; colour of oxide - white
  • melting point in $$^{o}C$$ - 328; density in $$g/{cm}^{3}$$- 11.3; colour of oxide - yellow
  • melting point in $$^{o}C$$ - 651; density in $$g/{cm}^{3}$$- 1.7; colour of oxide - white
  • melting point in $$^{o}C$$ - 1240; density in $$g/{cm}^{3}$$- 7.4; colour of oxide - black
$$E _ { 1 },\  E _ { 2 }$$  and  $$E _ { 3 }$$  are the emf values of the three galvanic cells respectively.
(a) $$Zn\left| Zn_{ { 1M } }^{ { +2 } } \right| \left| Cu_{ { 0.1M } }^{ { +2 } } \right| Cu$$
(b) $$Zn\left| Zn_{ { 1M } }^{ { +2 } } \right| \left| Cu_{ { 1M } }^{ { +2 } } \right| Cu$$
(c) $$Zn\left| Zn_{ { 0.1M } }^{ { +2 } } \right| \left| Cu_{ { 1M } }^{ { +2 } } \right| Cu$$
Which one of the following is true?
  • $$\mathrm { E } _ { 2 } > \mathrm { E } _ { 3 } > \mathrm { E } _ { 1 }$$
  • $$\mathrm { E } _ { 3 } > \mathrm { E } _ { 2 } > \mathrm { E } _ { 1 }$$
  • $$\mathrm { E } _ { 1 } > \mathrm { E } _ { 2 } > \mathrm { E } _ { 3 }$$
  • $$\mathrm { E } _ { 1 } > \mathrm { E } _ { 3 } > \mathrm { E } _ { 2 }$$
Which of the following pair has similar magnetic moment?
  • $$Cr^{3+}, Mn^{3+}$$
  • $$Fe^{3+}, Mn^{2+}$$
  • $$Fe^{2+}, Mn^{2+}$$
  • $$Ni^{2+}, Co^{2+}$$
$$Gd\ (64)$$ has _________ unpaired electrons with sum of spin __________.
  • $$7, 3.5$$
  • $$8, 3$$
  • $$6, 3$$
  • $$8, 4$$
  • $$9, 3.5$$
Amphoteric behaviour is shown by the oxides of:
  • $$Al$$ and $$Ca$$
  • $$Pb$$ and $$Ba$$
  • $$Cr$$ and $$Mg$$
  • $$Sn$$ and $$Zn$$
The first IE of lithium is $$5.4$$eV and first electron affinity of $$Cl$$ is $$3.6$$eV. The value of $$\Delta H$$ for the reaction $$Li_{(g)} + Cl_(g) \rightarrow Li^{+}_{(g)} + Cl^{-} _{(g)}$$, is (in eV) :
  • $$+1.8$$
  • $$+ 2.8$$
  • $$- 2.8$$
  • $$+ 9$$
Potassium dichromate can be prepared by:
  • heating $$Na_{2}Cr_2O_{7}$$ solution with $$KCl$$ solution and then cooling.
  • heating powdered chromite ore with quicklime in the presence of air
  • heating $$K_{2}CrO_{4}$$ with sulphuric acid
  • both $$A$$ and $$C$$
The magnetic moment of $$[Cu(NH_{3})_{4}]^{2+}$$ was found to be 1.73 B.M. The number of unpaired electrons in the complex is:
  • 0
  • 1
  • 2
  • 3
$$AgCl$$ and $$NaCl$$ are colourless. $$NaBr$$ and $$NaI$$ are also colourless but $$AgBr$$ and $$AgI$$ are coloured. This is due to:
  • $$ Ag^+$$ polarizes $$Br^-$$ and $$I^- $$
  • $$ Ag^+ $$ has unpaired d - orbital
  • $$ Ag^+ $$ depolarizes $$ Br^-$$ and $$I^- $$
  • None is correct
Which of the following types of metals forms the most efficient catalysts
  • Alkali metals
  • Alkaline earth metals
  • Transition metal
  • All of these
Which of the following statements is not true in regard to transition elements? 
  • They readily form complex compounds
  • They show variable valency
  • All their ions are colourless
  • Their ions contain partially filled d -electron levels
Transitional elements are named transition elements because their characters are 
  • in between s and p - block elements
  • like that of p and d - block elements
  • they are members of I – A group
  • they are like inactive elements
Which forms coloured salts? 
  • Metals
  • Non-metals
  • p-block elements
  • Transitional elements
Which of the following ions having the following electronic structure would have a maximum magnetic moment?
  • $$1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^23d^{3}$$
  • $$1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^23d^{5}$$
  • $$1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^23d^{7}$$
  • $$1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^23d^{9}$$
Titanium shows the magnetic moment of 1.73 BM. in its compound. What is the oxidation number of $$Ti$$ in the compound?
  • +1
  • +4
  • +3
  • +2
If the colours of salts of transition elements are due to the presence of unpaired electrons in the transition metal ions, which of the following ions will be colourless in aqueous solution.
  • $$ Ti^{3+} $$
  • $$ Ti^{4+} $$
  • $$ Fe^{2+} $$
  • $$ Fe^{3+} $$
The correct order of atomic radii is:
  • $$Yb^{3+}< Pm^{3+}< Ce^{3+}< La^{3+}$$
  • $$Ce^{3+}< Yb^{3+}< Pm^{3+}< La^{3+}$$
  • $$Yb^{3+}< Pm^{3+}< La^{3+}< Ce^{3+}$$
  • $$Pm^{3+}< La^{3+}< Ce^{3+}< Yb^{3+}$$
Iron sheets are covered with a layer of zinc i.e., galvanized mainly to:
  • harden the surface
  • increase the surface
  • prevent action of water only
  • prevent action of oxygen and water
Which of the following belongs to actinoid series of elements?
  • Nd
  • U
  • Sm
  • Au
In the dichromate anion,
  • 4 $$Cr-O$$ bonds are equivalent
  • 6 $$Cr-O$$ bonds are equivalent
  • all $$Cr-O$$ bonds are equivalent
  • all $$Cr-O$$ bonds are non-equivalent
Which compound is volatile on heating?
  • $$MgCl_{2}$$
  • $$HgCl_{2}$$
  • $$ZnCl_{2}$$
  • none of these
Which of the following ions has the least magnetic moment?
  • $$ Cu^{2+} $$
  • $$ Ni^{2+} $$
  • $$ Co^{3+} $$
  • $$ Fe^{2+} $$
Which of the following is diamagnetic transitional metal ion?
  • $$Ni^{2+} $$
  • $$ Zn^{2+} $$
  • $$ Co^{2+} $$
  • $$ Cu^{2+} $$
Which of the following is not true for transition metals? 
  • They are malleable and ductile
  • They have high boiling and melting points
  • They crystallize with body centred cubic and hexagonal close-packed structures only
  • They show variable oxidation states although not always
The elements belonging to the first transition series have an atomic number from 
  • 19 to 37
  • 22 to 32
  • 24 to 30
  • 21 to 30
Which is not true for transition elements?
  • They are all metals
  • They show variable valency
  • They form coloured ions
  • They do not form co-ordinate compounds
Cuprous ion is colourless while cupric ion is coloured because
  • Both have half filled p and d-orbitals
  • Cuprous ion has incomplete d-orbital and cupric ion has a completely filled d-orbital
  • Both have unpaired electrons in the d-orbitals
  • Cuprous ion has a completely filled d-orbital and cupric ion has an incomplete d-orbital
Which of the following will give green hydrated ion?
  • $$ Fe^{2+} $$
  • $$ Ni^{2+ } $$
  • (A) and (B) both
  • $$ V^{3+} $$
$$ Fe^{2+} $$ shows 
  • Paramagnetism
  • Diamagnetism
  • None of these
  • Ferromagnetism
The first ionisation potential of $$N, P, O$$ and $$S$$ are in the order of:
  • $$S > P < O > N$$
  • $$N > O > P > S$$
  • $$N > O < P > S$$
  • $$N < O < P < S$$
The Lanthanoids contraction relates to:
  • atomic radii
  • atomic as well as $$M^{3+}$$ radii
  • valence electrons
  • oxidation states.
Which of the following cannot form oxo ion?
  • $$PuO_{2}^{+}$$
  • $$CeO_{2}^{+}$$
  • $$UO_{2}^{2+}$$
  • $$NpO_{2}^{+}$$
For which of the following transition metal ion is shown highest magnetic moment having outer electronic configuration 
  • $$ 3d^1 $$
  • $$ 3d^8 $$
  • $$ 3d^5 $$
  • $$ 3d^7 $$
Which of the following ions is coloured? 
  • $$ Cu^+ $$
  • $$ Cu^{2+} $$
  • $$ Ti^{4+} $$
  • $$ V^{5+} $$
Which one of the following properties is not of transition elements?
  • Colour
  • Paramagnetism
  • Fixed valency
  • None of the above

Number of $$Cr-O$$ bonds in dichromate ion$$(Cr_{2}O_{7}^{2-})$$ is:
  • 6
  • 7
  • 8
  • 4

IP values of Sc, Y and La are in the order:
  • Sc > Y > La
  • Sc < Y < La
  • Sc = Y = La
  • La > Sc > Y
Which statement is not true ?
  • Zn is a transition metal.
  • Ag is coinese metal.
  • Density of Osmium is the greatest.
  • All of the above.
Which of the following metals make the most efficient catalyst?
  • Transition
  • Alkali
  • Alkaline earth
  • Coloured metals
Which belongs to the actinides series?
  • $$ Ce $$
  • $$ Cf $$
  • $$ Ca $$
  • $$ Cs $$
The 3d-metal ions are paramagnetic in nature because 
  • They are reducing agents
  • They form coloured salt
  • They have one or more paired s-electrons
  • They have one or more unpaired d-electrons
Which of the following metals absorbs hydrogen? 
  • K
  • Al
  • Zn
  • Pd
The correct order of ionic radii of $$Y^{3+}, La^{3+}, Eu^{3+}$$ and $$Lu^{3+}$$ is:
(Atomic number of Y=39, La=57, Eu=63, Lu=71)
  • $$Lu^{3+} < Eu^{3+} < La^{3+} < Y^{3+}$$
  • $$La^{3+} < Eu^{3+} < Lu^{3+} < Y^{3+}$$
  • $$Y^{3+} < La^{3+} < Eu^{3+} < Lu^{3+}$$
  • $$Y^{3+} < Lu^{3+} < Eu^{3+} < La^{3+}$$
The aqueous solution of the salt will colored in the case of:
  • $$Zn{({NO}_{3})}_{2}$$
  • $$Li{NO}_{3}$$
  • $$Co{({NO}_{3})}_{2}$$
  • $$Cr{Cl}_{3}$$
Which of the following represents the correct order of the properties indicated?
  • $${Ni}^{2+}> {Cr}^{2+}> {Fe}^{2+}> {Mn}^{2+}$$ (size)
  • $$Sc> Ti> Cr> Mn$$ (size)
  • $${Ni}^{2+}< {Co}^{2+}< {Fe}^{2+}< {Mn}^{2+}$$ (unpaired electron)
  • $${Cr}^{3+}> {Cr}^{2+}$$ (magnetic moment)
The color of the transition metal ions is due to:
  • $$d-d$$ transition
  • charge transfer
  • change in the geometry
  • none
In which of the following. tendency towards formation of coloured ions is maximum
  • s-block elements
  • d-block elements
  • p-block elements
  • f-block elements
What is/are true statement?
  • Ions of $$d$$-block elements are colored due to $$d-d$$ transition
  • Ions of $$f$$-block elements are colored due to $$f-f$$ transtition
  • $${ \left[ Sc{ \left( { H }_{ 2 }O \right) }_{ 6 } \right] }^{ 3+ },{ \left[ Ti{ \left( { H }_{ 2 }O \right) }_{ 6 } \right] }^{ 4+ }$$ are colored complexes.
  • $${Cu}^{+}$$ is colorless ion.
Magnetic moment $$\sqrt{35}$$ is true for which of the following pair :
  • $$Co^{+2}, Fe^{+2}$$
  • $$Fe^{+3}, Mn^{+2}$$
  • $$Co^{+3}, Cr^{+2}$$
  • $$Fe^{+2}, Mn^{+2}$$
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