CBSE Questions for Class 12 Engineering Chemistry The D-And F-Block Elements Quiz 9 - MCQExams.com

$$2Cr_4^{2-} \underset{Y}{\overset{ X  }{\rightleftharpoons}}Cr_2O_7^{2-}$$, $$X$$ and $$Y$$ are respectively:
  • $$X = OH^-, \, Y = H^+$$
  • $$X = H^+, \, Y = OH^-$$
  • $$X = OH^-, \, Y = H_2O_2$$
  • $$X = H_2O_2, \, Y = OH^-$$
The spin only magnetic moment of $$Mn^{4+}$$ ion is nearly:
  • $$3\ BM$$
  • $$6\ BM$$
  • $$4\ BM$$
  • $$5\ BM$$
Magnetic moment of $${X^{3 + }}$$ion od $$3d$$ series is $$\sqrt {35} \,BM$$. What is atomic number of $${X^{3 + }}$$?
  • $$25$$
  • $$26$$
  • $$27$$
  • $$28$$
Which has the maximum magnetic moment?
  • $$Mn^{2+}$$
  • $$Fe^{2+}$$
  • $$Ti^{2+}$$
  • $$Cr^{2+}$$
Magnetic moment of $${}_{{\text{25}}}{\text{M}}{{\text{n}}^{{\text{x + }}}}{\text{ is }}\sqrt {{\text{15}}} $$ B.M then the value of x is :
  • 1
  • 2
  • 3
  • 4
Which one of the following ion(s) is/are paramagnetic?
  • $$Al^{3+}$$
  • $$Fe^{2+}$$
  • $$K^+$$
  • $$Mg^{2+}$$
Magnetic moment $$2.83\ BM$$ is given by which of the following ions?
(At. nos. $$Ti=22,Cr=24,Mn=25,Ni=28$$)
  • $${Ti}^{3+}$$
  • $${Ni}^{2+}$$
  • $${Cr}^{3+}$$
  • $${Mn}^{2+}$$
Which of the following becomes paramagnetic on heating?
  • $$MnO$$
  • $$Fe_3O_4$$
  • $$ZnFe_2O_4$$
  • $$B$$ and $$C$$ both
Actinoids belongs to following type of elements:
  • s -block element
  • d -block element
  • f -block element
  • p -block element
A complex $${\left[ {M{F_6}} \right]^{ - x}}$$ has magnetic moment of 4.91 B.M. whereas $${\left[ {M{{(CN)}_6}} \right]^{ - x}}$$ has zero magnetic moment, metal ion can be :
  • $$C{o^{ + 2}}$$
  • $$M{n^{ + 2}}$$
  • $$F{e^{ + 2}}$$
  • $$F{e^{ + 3}}$$
Which of the following is diamagnatie?
  • $$Cr^{3+}$$
  • $$V^{2+}$$
  • $$Sc^{3+}$$
  • none
Figure 
1438517_6c2bc5a6a669425d8ff80548f3e446b6.png
  • Ethane
  • Propane
  • n- Butane
  • n-pentane
Compare magnetic moment of $$Mn,{ Mn }^{ + },{ Mn }^{ 2+ },{ Mn }^{ 3+ }:$$
  • $${ Mn }^{ 3+ }>Mn>{ Mn }^{ 2+ }>{ Mn }^{ + }$$
  • $${ Mn }^{ + }>Mn^{ 2+ }>{ Mn }^{ 3+ }>{ Mn }$$
  • $$Mn={ Mn }^{ 2+ }>Mn^{ 3+ }>{ Mn }^{ + }$$
  • $${ Mn }^{ + }>Mn=Mn^{ 2+ }>{ Mn }^{ 3+ }$$
The magnetic moment for  $${ Ti }^{ 2+ }$$, $${ V }^{ 3+ }$$ and $${ Ni }^{ 2+ }$$ is ________ .
  • 4.90
  • 3.87
  • 2.83
  • 1.73
Which of the following compounds are coloured due to charge transfer spectra?
  • $${K}_{2}{Cr}_{2}{O}_{7}$$
  • $$KMn{O}_{4}$$
  • $$Cu{SO}_{4}.5{H}_{2}O$$
  • Both (A) and (C)
Uranium is a radioactive element but it is also a typical metal. What is not a property of uranium?
  • It can be hammered into shape
  • It conducts heat
  • It is used as a source of energy
  • It forms covalent compounds
In $$Sc^{3+},Ti^{2+},Ti^{3+},V^{2+}$$, increasing order of spin only magnetic moment is:
  • $$Sc^{3+} < Ti^{2+} < Ti^{3+}< V^{2+}$$
  • $$Sc^{3+} < Ti^{3+} < Ti^{2+}< V^{2+}$$
  • $$Ti^{2+} < Sc^{3+} < Ti^{3+}< V^{2+}$$
  • $$Sc^{3+} < Ti^{2+} < V^{2+}< Ti^{3+}$$
Transition metal compounds are usually colored. This is due to the electronic transition
  • from p-orbital to s-orbital
  • from d-orbital to s-orbital
  • from d-orbital to p-orbital
  • within the d-orbitals
Which of the following statements is correct for the complex, $$K_4[Fe(CN)_5O_2]$$ having $$t^6_{2g}, e^0_g$$ electronic configuration?
  • $$d^2sp^3$$ hybridized and diamagnetic
  • $$sp^3d^2$$ hybridized and paramagnetic
  • $$sp^3d^2$$ hybridized and diamagnetic
  • $$d^2sp^3$$ hybridized and paramagnetic
Choose the true statement regarding compounds X and Y.
  • Both compounds X and Y have different magnetic moment(spin only)
  • Both complexes X and Y have same magnetic moment(spin only)
  • Magnetic moment of both X and Y is calculated by assuming they are low-spin complex
  • Both compounds X and Y have different primary valency
Among the following the lowest degree of paramagnetism per mole of the compound at $$298$$K will be shown by?
  • $$MnSO_4\cdot 4H_2O$$
  • $$FeSO_4\cdot H_2O$$
  • $$CuSO_4\cdot 5H_2O$$
  • $$NiSO_4\cdot 6H_2O$$
Which of the following statements is correct?
  • With $$d^2sp^3$$ hybridization, $$[FeCl(CN)_4(O_2)]^{4-}$$ complex is diamagnetic.
  • $$[NiCl_4]^{2-}$$ complex is more stable than $$[Ni(dmg)_2]$$ due to higher C.F.S.E. value.
  • $$[V(CO)_6]$$ is not very stable and easily reduces to $$[V(CO)_6]^-$$.
  • Ligands such as $$CO, CN^-, NO^+$$ are $$\pi e^-$$ donor due to the presence of filled $$\pi$$-molecular orbital.
An aqueous solution of titanium chloride, when subjected to magnetic measurement, measured zero magnetic moment. Assuming the complex as octahedral in aqueous solution, the formula of the complex is?
  • $$[Ti(H_2O)_6]Cl_2$$
  • $$[Ti(H_2O)_6]Cl_4$$
  • $$[TiCl_6]^{3-}$$
  • $$[Ti(H_2O)_4Cl_2]$$
Atomic numbers of $$Cr$$ and $$Fe$$ are, respectively, $$24$$ and $$26$$. Which of the following is paramagnetic with spin of electron?
  • $$Cr(CO)_6$$
  • $$[Fe(CO)_5]$$
  • $$[Fe(CN)_6]^{4-}$$
  • $$[Cr(NH_3)_6]^{3+}$$
The d-electron configurations of $$Mn^{2+}, Fe^{2+}, Co^{3+}$$ and $$Ni^{2+}$$ are $$3d^5, 3d^6, 3d^6, 3d^8$$, respectively. Which of the following aqua complexes will exhibit the minimum paramagnetic behavior? 
  • $$[Fe(H_2O)_6]^{2+}$$
  • $$[Co(H_2O)_6]^{3+}$$
  • $$[Ni(H_2O)_6]^{2+}$$
  • $$[Mn(H_2O)_6]^{2+}$$
The color of $$Cu^+$$ compounds is?
  • White
  • Blue
  • Orange
  • Yellow
The complex $$[Fe(H_3O)_5NO]^{2+}$$ is formed in the brown ring test for nitrates when freshly prepared $$FeSO_4$$ solution is added to an aqueous solution of $$NO^-_3$$ followed by addition of conc. $$H_2SO_4$$. Select correct statements about this complex:
  • Color change is due to charge transfer
  • It has iron in $$+1$$ oxidation state and nitrosyl as $$NO^+$$
  • It has magnetic moment of $$3.87$$ B.M. confirming three unpaired electrons in Fe
  • In complex Fe has $$d^2sp^3$$ hybridization
$$ K_2 [HgI_4] $$ detects the ion/group:
  • $$ NH^-_2 $$
  • $$NO$$
  • $$ NH_4^+ $$
  • $$ AlCl_3 $$
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 colorless spccits is:
  • $$ VCI_3 $$
  • $$ VOSO_4 $$
  • $$ Na_3 VO_4 $$
  • $$ [V(H_2O]SO_4] H_2O $$
Yellow color solution of $$ FeCl_{3} $$ changew to light green when
  • $$ SnCl_{2} $$ is added
  • Zn is added
  • $$ H_{2}S $$ gas is passed
  • All are true
For Ni and pt dofferent L.P. in KJ $$ mol^{-1} $$ are given below.
$$ \frac { (IP)_ 1+(IP)_ 2 }{ \overset { Ni }{ Pt } \quad \quad \quad \quad \overset { 2.49 }{ 2.60 }  }   \frac { (IP)_ 3+(IP)_ 4 }{ \overset { 8.80 }{ 6.70 }  } $$
  • Nickel (II) compounds tend to be thermodynami -cally more stable than platinum (II)
  • Platinum (IV) compounds lend to be more stable than nickel (IV)
  • Both are correct
  • None is correct
In $$ Cr_2O_7^{-2} $$ every Cr is linked to :
  • Two O-atoms
  • Three O-atoms
  • Four O-atoms
  • Five O-atoms
Elements which generally exhibit multiple oxidation states and whose ions are usually coloured are 
  • Metalloids
  • Transition elements
  • Non-metals
  • Gases
$$ Ti^{2+}$$ is purple while $$ Ti^{4+} $$ is colorless,because:
  • There is no crystal field effect in $$ Ti^{4+} $$
  • $$ Ti^{4+}$$ has $$3d^2 $$ configuration
  • $$ Ti^{4+}$$ has $$3d^0 $$ configuration
  • $$ Ti^{4+} $$ is a very small cation when compared to $$ Ti^{2+} $$ and hence does not absorb any radiation
Increasing basic properties of $$ TiO_2$$, $$ZrO_2$$ and $$HfO_2 $$ are in order. 
  • $$ TiO_2 < ZrO_2 < HfO_2 $$
  • $$ HfO_2 < ZrO_2 < TiO_2 $$
  • $$ HfO_2 < TiO_2 < ZrO_2 $$
  • $$ ZrO_2 < TiO_2 < HfO_2 $$
In the dichoromate dianion:-
  • Four Cr-O bonds are equivalent
  • Six Cr-O bonds are equivalent
  • All Cr-O bonds are equivalent
  • All Cr-O bonds are non-equivalent
One heating ammonium dichromate, the gas evolved is: 
  • Oxygen
  • Ammonia
  • Nitrous oxide
  • Nitrogen
Out of $$ [Fe(CN)_6]^{4-} , [Ni(CN)_4]^{2-} ,$$ and $$[Ni(CO)_4] $$ select the incorrect statements.
  • All have identical geometry
  • All are paramagnetic
  • All are diamagnetic
  • $$[Fe(CN)_6]^{4-} $$ is diamagnetic but $$ [Ni(CN)_4]^{2-} $$ and $$[Ni(CO)_4] $$ are paramagnetic
Which of the following ions show higher spin only magnetic moment value ?
  • $$ Ti^{3+} $$
  • $$ Mn^{2+} $$
  • $$ Fe^{3+} $$
  • $$ Co^{3+} $$
In $$ [Fe(CN)_5(NO)]^{2-}, Fe $$ has +2 state. It cannot be decided by.
  • Magnetic measurement
  • Colligative property
  • Colour
  • Hybridization
In the dichromate dianoin:
  • Four Cr-O bonds are equivalent
  • Six Cr-O bonds equivalent
  • All Cr-O bonds are equivalent
  • All Cr-O bonds are non-equivalent
In context of the lanthanoids , which of the following statements is not correct ?
  • There is gradual decrease in the raddi of the members with increasing atomic number in the series
  • All the members exhibit $$+3$$ oxidation state
  • Because of similar properties, the separation of lanthanoids is not easy
  • Availability of $$4f$$ electrons results in the formation of compounds in $$+4$$ state for all the members of the series.
The correct statement about the magnetic properties of $$[Fe(CN)_6]^{3-}$$ and $$[FeF_6]^{3-}$$ is: $$(Z=26)$$.
  • $$[Fe(CN)_6]^{3-}$$ is paramagnetic, $$[FeF_6]^{3-}$$ is diamagnetic
  • Both are diamagnetic
  • $$[Fe(CN)_6]^{3-}$$ is diamagnetic, $$[FeF_6]^{3-}$$ is paramagnetic
  • Both are paramagnetic
Hg is found in nature as HgS because :
  • $$Hg^{2+}$$ is soft acid and $$S^{2-}$$ soft base
  • Lattice energy of HgS is high
  • Hg and S are close in periodic table
  • Ionisation energy of Hg is very high
Which one of the following cyano complexes would exhibit the lowest value of paramagnetic behaviour?
  • $$[Co(CN)_6]^{3-}$$
  • $$[Fe(CN)_6]^{3-}$$
  • $$[Mn(CN)_6]^{3-}$$
  • $$[Cr(CN)_6]^{3-}$$
The electronic configuration of actinoids can not be assigned with degree of certanity because of :
  • overlapping of inner orbitals
  • free movement of electron over all the orbitals
  • small energy difference between $$5f$$ and $$6d$$ levels
  • none of above
Lanthanoid contraction implies :
  • Decrease in density
  • Decreases in mass
  • Decrease in ionic radii
  • Decrease in radioactivity
Most of the man-made synthetic elements occur:
  • in actinide series
  • in lanthanide series
  • in coinage metals
  • in alkaline earth metals
Arrange $$ Ce^{3+} , La^{3+} ,Pm^{3+}$$ and $$Yb^{3+} $$ in increasing order of their ionic radii:
  • $$ Yb^{3+} < Pm^{3+} < Ce^{3+} < La^{3+} $$
  • $$ Yb^{3+} < Pm^{3+} < La^{3+} < Ce^{3+} $$
  • $$ La^{3+} < Ce^{3+} < Yb^{3+} < Pm^{3+} $$
  • $$ Pm^{3+} < La^{3+} < Ce^{3+} < Yb^{3+}$$
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