CBSE Questions for Class 12 Engineering Chemistry The D-And F-Block Elements Quiz 13 - MCQExams.com

Identify the incorrect statement in the following
  • d block elements show irregular and erratic chemical properties among themselves.
  • La and Lu have partially filled d-orbital and no other partially filled orbital.
  • The chemistry of various Lanthanoids is similar.
  • 4f and 5f orbitals are equally shielded.
The thermal decomposition of ammonium dichromate produces a green residue of:
  • $$Cr_2O_3$$
  • $$CrO_2$$
  • $$CrO_3$$
  • $$CrO_5$$
Number of identical $$Cr-O$$ bonds in dichromate ion $${Cr_2{ O }_{ 7 }}^{ 2- }$$ is:
  • 4
  • 6
  • 7
  • 8
$$\left[ Cr\left( { H }_{ 2 }O \right) _{ 6 }{ Cl }_{ 3 } \right] $$ has a magnetic moment of 3.83 BM. The correct distribution of 3d electrons in the chromium atom in the complex is:
  • $${ 3d }_{ xy }^{ 1 },{ 3d }_{ yz }^{ 1 },{ 3d }_{ { z }^{ 2 } }^{ 1 }$$
  • $${ 3d }_{ \left( { x }^{ 2 }-{ y }^{ 2 } \right)} ^1 ,{ 3d }_{ z^2 }^{ 1 },{ 3d }_{ xz }^{ 1 }$$
  • $${ 3d }_{ xy }^{ 1 },{ 3d }_{ \left( { x }^{ 2 }-{ y }^{ 2 } \right) }^1,{ 3d }_{ z }^{ 1 }$$
  • $${ 3d }_{ xy }^{ 1 },{ 3d }_{ yz }^{ 1 },{ 3d }_{ { xz } }^{ 1 }$$
For which of the following elements all of its existing ion, $$M^{x+}$$, will be diamagnetic?
  • $$Cu$$
  • $$Fe$$
  • $$Cr$$
  • $$Na$$
A transition metal $$A$$ has spin only magnetic moment value of $$1.8\ B.M$$. When it is reacted with dilute $$H_2SO_4$$ in presence of air, its compound $$B$$ reacts with compound $$C$$ to give compound $$D$$ with liberation of iodine. Then the metal $$A$$, and compounds $$B, C$$ and $$D$$ are respectively:
  • $$Ti, TiSO_4, KI$$ and $$TiI_2$$
  • $$An, ZnSO_4, KI$$ and $$ZnI_2$$
  • $$Cu, CuSO_4, KI$$ and $$Cu_2I_2$$
  • $$Cu, CuSO_4, KI$$ and $$CuI_2$$
Match the catalysts (Column I) with products column (II)
Column IColumn II
(A) $${V}_{2}{O}_{5}$$(i) Polyethylene
(B) $$Ti{Cl}_{4}/Al{(Me)}_{3}$$(ii) ethanal
(C) $$Pd{Cl}_{2}$$(iii) $${H}_{2}{SO}_{4}$$
(D) Iron Oxide(iv) $${NH}_{3}$$
  • (A)- (ii); (B)- (iii); (C)- (i); (D)- (iv)
  • (A)- (iii); (B)- (i); (C)- (ii); (D)- (iv)
  • (A)- (iii); (B)- (iv); (C)- (i); (D)- (ii)
  • (A)- (iv); (B)- (iii); (C)- (ii); (D)- (i)
Match the following catalyst with their products-
SrColumn 1SrColumn 2
1.$$TiCl_4+AlCl_3$$a.Ethanal
2.$$V_2O_5$$b.$$NH_3$$
3.$$Fe$$c.Polyethylene
4.$$Pd$$d.$$H_2SO_4$$
  • $$(i)-B ; (ii)-A ; (iii)-D ; (iv)-C$$
  • $$(i)-C ; (ii)-D ; (iii)-B ; (iv)-A$$
  • $$(i)-D ; (ii)-A ; (iii)-B; (iv)-C$$
  • $$(i)-A ; (ii)-B ; (iii)-C ; (iv)-D$$
Consider the hydrates ions of $$Ti^{2+}, V^{2+}, Ti^{3+}$$ and $$Sc^{3+}$$. The correct order of their spin-only magnetic moments is:
  • $$Sc^{3+} < Ti^{3+} < Ti^{2+} < V^{2+}$$
  • $$Ti^{3+} < Ti^{2+} < Sc^{3+} < V^{2+}$$
  • $$Sc^{3+} < Ti^{3+} < V^{2+} < Ti^{2+}$$
  • $$V^{2+} < Ti^{2+} < Ti^{3+} < Sc^{3+}$$
What is the value of spin only magnetic moment of anionic and cationic part of complex $${\left[ Fe{ \left( { H }_{ 2 }O \right)  }_{ 6 } \right] }_{2}$$ $$\left[ Fe{ \left( CN \right)  }_{ 6 } \right] $$?
  • $$4.9$$ B.M and Zero
  • Zero and $$4.9$$ B.M
  • $$2.9$$ B.M and $$0$$
  • $$0$$ and $$2.9$$ B.M
Photochromic glass, used for sunglasses, darkens when exposed to bright light and becomes
more transparent again when the light is less bright. The darkness of the glass is related to the
concentration of silver atoms.
The following reactions are involved.
reaction 1 $$Ag^{+}  + Cl^{-}\rightleftharpoons Ag + Cl$$
reaction 2 $$Cu^{+} + Cl \rightarrow Cu^{2+} + Cl^{-}$$
reaction 3 $$Cu^{2+} + Ag \rightarrow Cu^{+}  + Ag^{+}$$
Which statement about these reactions is correct?
  • $$Cu^{+}$$ and $$Cu^{2+}$$ ions act as catalysts
  • $$Cu^{+}$$ ions act as an oxidising agent in reaction $$2$$
  • Reaction $$3$$ increases the darkness of the glass
  • Silver atoms are reduced in reaction $$3$$
The calculated spin-only magnetic moments (BM) of the anionic and cationic species of $$[Fe(H_2O)_6]_2$$ and $$[Fe(CN)_6]$$, respectively, are:
  • $$4.9$$ and $$0$$
  • $$2.84$$ and $$5.92$$
  • $$0$$ and $$4.9$$
  • $$0$$ and $$5.92$$
The INCORRECT statement is:
  • The spin - only magnetic moments of $$[Fe(H_{2}O)_{6}]^{2+}$$ and $$[Cr(H_{2}O)_{6}]^{2+}$$ are nearly similar
  • The spin-only magnetic moment of $$[Ni(NH_{3})_{4}(H_{2}O)_{2}]^{2+}$$ is $$2.83\ BM$$
  • The gemstone, ruby, has $$Cr^{3+}$$ ions occupying the octahedral sites of beryl
  • The color of $$[CoCl (NH_{3})_{5}]^{2+}$$ is violet as it absorbs the yellow light
Which of the following complex is paramagnetic?
  • $$K_2[Ni(CN)_4]$$
  • $$K_4[Fe(CN)_6]$$
  • $$[Co(NH_3)_6]Cl_3$$
  • $$[Cr(H_2O)_6]SO_4$$
Which of the pair of complex compounds are tetrahedral as well as diamagnetic?
  • $$[CoCl_4]^-$$ and $$[Co(CO)_4]^-$$
  • $$[Ag(SCN)_4]^{2-}$$ and $$[NiCl_4]^{2-}$$
  • $$[Co(CO)_4]^-$$ and $$[Ni(CN)_4]^{4-}$$
  • $$[PdCl_4]^{2-}$$ and $$[Ni(CN)_4]^{2-}$$
The magnetic moment of a certain complex(A) of Co was found to be $$4.89$$ B.M. and the EAN as $$36$$. Co also forms complex(B) with magnetic moment $$3.87$$ B.M. and EAN $$37$$, and complex(C) with EAN as $$36$$ but diamagnetic. Which of the following statements is true regarding the above observation?
  • The oxidation states of Co in (A), (B) and (C) are $$+3, +2$$ and $$+3$$, respectively
  • Complexes (A) and (B) have $$sp^3d^2$$ hybridization state while (C) has $$dsp^3$$ hybridizaiton state
  • The spin multiplicities of Co in (A), (B) and (C) are $$4, 3$$ and $$1$$, respectively
  • The oxidation states of Co in (A), (B) and (C) are $$+6, +8$ and $$+1$$, respectively
Which of the following complexes has magnetic moment of $$2.83$$ Bohr magneton?
  • $$[Ni(NH_3)_6]^{2+}$$
  • $$[Ni(CN)_4]^{2-}$$
  • $$TiCl_4$$
  • $$[CoCl_6]^{3-}$$
In the hydrogenenation of oil :-
  • $$Ni$$ acts as a promoter
  • $$Cu$$ acts as a catalyst
  • Tellurium acts as a promoter
  • $$Ni$$ acts as a catalyst
Among the following ions which one has the highest paramagnesium?
  • $$[Cr(H_2O)_6]^{3+}$$
  • $$[Fe(H_2O)_6]^{2+}$$
  • $$[Cu(H_2O)_6]^{2+}$$
  • $$[Zn(H_2O)_6[^{2+}$$
Which of the following anion exists in equilibrium condition with other anion depending upon the pH of the solution? 
  • $$ CrO^{2-}_{4} $$
  • $$ SO^{2-}_{4} $$
  • $$ CO^{2-}_{3} $$
  • $$ SO^{2-}_{3}$$
Which of the following is incorrect about Wilkinson's catalyst?
  • It is a non-ionic complex
  • It is a diamagnetic complex
  • It is a tetrahedral complex
  • It is very effective for selective hydrogenation of organic molecule at room temperature and pressure
Which of the following complex(s) is/are paramagnetic in nature?
  • $$K_2[NiF_6]$$
  • $$K_3[CoF_6]$$
  • $$K_3[Fe(CN)_6]$$
  • $$[Co(H_2O)_6]^{3+}$$
Which of the following complex ion(s) are paramagnetic?
  • $$[Ni(CN)_4]^{2-}$$
  • $$[NiCl_4]^{2-}$$
  • $$[CoF_6]^{3-}$$
  • $$[Co(NH_3)_6]^{3+}$$
Select the paramagnetic complex compound.
  • $$K_4[Fe(CN)_5O_2]$$
  • $$Fe(CO)_5$$
  • $$[Cr(NH_3)_6]^{3+}$$
  • $$[Ni(CN)_6]^{4-}$$
Which of the following statement(s) is/are correct?
  • $$Ni(CO)_4$$-Tetrahedral, paramagnetic
  • $$[Ni(CN)_4]^{2-}$$-Square planar, diamagnetic
  • $$[Ni(CO)_4]$$-Tetrahedral, diamagnetic
  • $$[NiCl_4]^{2-}$$-Tetrahedral, paramagnetic
Select the correct statement(s):
  • The transition metal ion is more polarizing compared to the alkali and alkaline earth metal ions of comparable size for a particular oxidation state
  • The solubility of silver halides in water runs as $$ AgF > AgCl > AgBr > AgI $$
  • $$LiCl$$ is soluble in organic solvents while $$NaCl$$ is insoluble in such solvents
  • All are incorrect
The pair(s) of reagents that yield paramagnetic species is/are:
  • Na and excess of $$NH_3$$
  • K and excess of $$O_2$$
  • Cu and dilute $$HNO_3$$
  • $$O_2$$ and 2-ethylanthraquinol
Which of the following complexes are diamagnetic?
  • $$[AuCl_4]$$
  • $$[Co(H_2O)_6]^{3+}$$
  • $$[CoF_6]^{3-}$$
  • $$[Co(CO)_4]^-$$
$$ Cr_2O^{2-}_7 \rightarrow{H^+} +Cr^{3+}.\ Eq.wt.of Cr_2O_7^{2-} $$ is 
  • mol.wt/6
  • mol wt./3
  • mol. wt/4
  • mol. wt/1
In the form of dichromate, Cr(VI) is a strong oxidizing agent in acidic medium but Mo(VI) in $$ MoO_3$$ and W(VI) in $$ WO_3 $$ are not because......
  • Cr(VI) is more stable than Mo(VI) and W (VI)
  • Mo(VI) and W(VI) are more stable than Cr(VI)
  • Higher oxidation states of heavier members of group-6 of transition series are more stable
  • Lower oxidation states of heavier members of group-6 of transition series are more stable.
Which of the following sulphide is yellow in colour?
  • $$CuS$$
  • $$CdS$$
  • $$ZnS$$
  • $$CoS$$
What are the species A and B in the following.

$$ CrO_3 + H_2O \rightarrow A \xrightarrow{OH^-} B $$
  • $$ H_2CrO_4 , H_2Cr_2O_7 $$
  • $$ H_2Cr_2O_7 , Cr_2O_3 $$
  • $$ CrO_4^{2-} , Cr_2O_7^{-2} $$
  • $$ H_2Cr_2O_7 , CrO_4^{2-} $$
Maximum magnetic moments of $$ Cr (Z = 24), Mn^{+} (Z=25),$$ and $$Fe^{2+} (Z=26), $$ are x, y, and z. They are in order:
  • x < y < z
  • x = z <y
  • z < x = y
  • x = y = z
The magnetic moment is associated with its spin angular momentum and orbital angular momentum,spin only magnetic value of $$ Cr^{3+} $$ ion is.......
  • 2.87 B.M
  • 3.87 B.M
  • 3.47 B.M
  • 3.57 B.M
Which of the following is a false statement?
  • $$ Cr^{2+} (g)$$ ion has greater magnetic moment compared to $$ Co^{3+} (g) $$
  • The magnitude of ionization potential of iron anion (monoanion) would be equal to electron gain enthalpy of iron
  • Lanthanoids contraction is cause of lower I.P. of Pb than Sn
  • If successive ionization energy are 332,738,849 , 4080,4958 (in Kj/mol) Then this element can be of 15 th group
Comprehension - 2 
 Potassium permanganate is prepared from the mineral pyrolusire $$ MnO_2 $$. Its crystal have deep purple color.It acts as an oxidizing agent in the netural,alkaline as well as acidic medium.In acidic medium,it is used in volumetric analysis for the estimation for ferrous salts,oxalates, etc.The titartion are carried out in the presence of $$ H_2SO_4 $$. However before using it as a titrant,it is first standardized with standard oxalic acid solution or Mohr salt solution.In one of the experiments on 13.4 g of dry pure sodium oxalate (molar mass = $$ 134 g mol^{-1} ) $$
 was disolved in 100 mL of distilled water and then 100 mL of distilled water and then 100 mL of $$ 2.M H_2 SO_4 $$ were added.The solution was cooled to $$ 25.30^oC $$.Now to this solution 0.1 M $$ KMnO_4 $$Solution was added till a very faints pink color persisted.
 (6) The purple color of $$ K_2 MnO_4 $$ is due to :
  • Incomplete d-subshell
  • Ionic nature of $$ KMnO_4 $$
  • Charge transfer
  • Resonance in $$ MnO^-_4 $$
The radius of $$ La^{3+} $$ (At . No of $$La =57$$ ) is $$ 1.06 \mathring{A} $$ which one of the following given values will be closest to the radius of $$ Lu^{3+}$$ (at no. of $$Lu = 71$$ ) ?
  • $$ 1.40 \mathring{A} $$
  • $$ 1.06  \mathring{A}  $$
  • $$ 0.85  \mathring{A} $$
  • $$ 1.60 \mathring{A} $$
Chloro compound of  vandium has only spin magnetic moment of 1.73 BM. This vanadium chloride has the formula (at.no V = 23)
  • $$ VCl_4 $$
  • $$ VCl_3 $$
  • $$ VCl_2 $$
  • $$ VCl_5 $$
Calomel $$ (Hg_2Cl_2) $$ on reaction with ammonium hydroxide gives:
  • $$HgO$$
  • $$ Hg_2O $$
  • $$ NH_2-Hg-Hg-Cl $$
  • $$ Hg NH_2Cl $$
Which of the following substance are green ?
  • $$ Fe(BO_{2})_{2} $$
  • $$Cu$$
  • $$ Cr(BO_{2})_{3} $$
  • $$ Co(BO_{2})_{2} $$
Which among the following are diamagnetic?
  • $$Cu^{2+}$$
  • $$Zn^{2+}$$
  • $$Ag^{+}$$
  • $$Cd^{2+}$$
General electronic configuration of actinodes is $$ (n-2)f^{1-14} (n-1)d^{0-2} ns^2 $$. Which of the following actinoids have one electrons in $$6d$$ orbitals?
  • $$U$$ (atomic no. $$92$$)
  • $$Np$$ (atomic no . $$93 $$)
  • $$Pu $$ ( atomic no.$$94 $$)
  • $$Am$$ ( Atomic no . $$95$$ )
$$ (NH_4)_2 Cr_2 O_7 $$ on heating gives a gas which is also given by:
  • Heating $$ NH_4NO_2 $$
  • Heating $$ NH_4NO_3 $$
  • $$ Mg_3N_2 + H_2O $$
  • Na(comp) + $$ H_2O_2 $$
On hearting ammonium dichromate the gas enolved is:
  • Oxygen
  • Ammonia
  • Nitrous oxide
  • Nitrogen
Among $$Ni(CO)_4, [Ni(CN)_4]^{2-}$$, and $$[NiCl_4]^{2-}$$.
  • $$Ni(CO)_4$$ and $$[NiCl_4]^{2-}$$ are diamagnetic and $$[Ni(CN)_4]^{2-}$$ is paramagnetic
  • $$[NiCl_4]^{2-}$$ and $$[Ni(CN)_4]^{2-}$$ are diamagnetic and $$Ni(CO)_4$$ is paramagnetic
  • $$Ni(CO)_4$$ and $$[Ni(CN)_4]^{2-}$$ are diamagnetic and $$[NiCl_4]^{2-}$$ is paramagnetic
  • $$Ni(CO)_4$$ is diamagnetic, and $$[NiCl_4]^{2-}$$ and $$[Ni(CN)_4]^{2-}$$ are paramagnetic
Among the following complexes $$(K-P)$$ 
$$K_3[Fe(CN)_6](K), [Co(NH_3)_6]Cl_3(L), $$ 

$$Na_3[Co(oxalate)_3](M), [Ni(H_2O)_6]Cl_2(N), $$

$$K_2[Pt(CN)_4](O)$$ and $$[Zn(H_2O)_6](NO_3)_2(P)$$

The diamagnetic are:
  • K, L, M, N
  • K, M, O, P
  • L, M, O, P
  • L, M, N, O
Match the complex ions gives in Column-I with the colors given in Column-II and assign the correct code.
Column-I(Complex ion)Column-II(Color)
(a) $$[Co(NH_3)_6]^{3+}$$(p) Violet
(b) $$[Ti(H_2O)_6]^{3+}$$(q) Green
(c) $$[Ni(H_2O)_6]^{2+}$$(r) Pale blue
(d) $$[Ni(H_2O)_4(en)]^{2+}(aq)$$(s) Yellowish orange
(t)Blue
  • a(p) b(q) c(s) d(t)
  • a(s) b(r) c(q) d(p)
  • a(r) b(q) c(s) d(p)
  • a(s) b(p) c(q) d(r)
The 'spin-only' magnetic moment [in units of Bohr magneton, $$(\mu_B)$$] of $$Ni^{2+}$$ in aqueous solution would be (atomic number of $$Ni=28$$).
  • $$6$$
  • $$1.73$$
  • $$2.84$$
  • $$4.90$$
Arrange the following ions in their magnetic moment:
(i) $$V^{4+}$$
(ii) $$Mn^{4+}$$
(iii) $$Fe^{3+}$$
(iv) $$Ni^{2+}$$
[At. Nos. $$V=23, Mn=25, Fe=26, Ni=28$$]
  • $$(ii)>(iii)>(i)>(iv)$$
  • $$(iii)>(iv)>(ii)>(i)$$
  • $$(iii)>(ii)>(iv)>(i)$$
  • $$(i)<(iv)<(iii)<(ii)$$
Which one of the following statements is correct?
  • $$[Cu(NH_3)_4]^{2+}$$ is diamagnetic while $$[Fe(CN)_6]^{4-}$$ is paramagnetic
  • $$[Cu(NH_3)_4]^{2+}$$ is paramagnetic while $$[Fe(CN)_6]^{4-}$$ is diamagnetic
  • Both are paramagnetic
  • Both are diamagnetic
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