CBSE Questions for Class 12 Engineering Chemistry The D-And F-Block Elements Quiz 7 - MCQExams.com

A transition element has an electronic configuration such that 4s orbital has only one electron. Which of the following is correct?
  • The element is $$Mg$$ and contains one electron in each of its 3d orbital
  • The element is $$Mg$$ and contains an empty 3d orbital
  • The element if $$Cr$$ and contains one electron in each of its 3d orbital
  • None of these
What is geometry of chromate ion?
  • Tetrahedral
  • Octahedral
  • Trigonal planer
  • Linear
In which pair highest oxidation states of transition metals are found?
  • Nitrides and Chlorides
  • Fluorides and Chlorides
  • Fluorides and Oxides
  • Nitrides and Oxides
____________ is used in gas lamp material.
  • $$MnO_2$$
  • $$CeO_2$$
  • $$N_2O_5$$
  • $$Fe_2O_3$$
Silver salt used in photography is:
  • $$AgCl$$
  • $$AgNO_3$$
  • $$AgF$$
  • $$AgBr$$
The metals present in Nichrome alloy is:
  • $$Cr,Ni,Fe$$
  • $$Cr,Co,Ni$$
  • $$Cr,Fe$$
  • $$Cr,Fe,Cu$$
Fuel used in nuclear power plants is:
  • Uranium - 235
  • Plutonium - 235
  • Plutonium - 238
  • Uranium - 238
Which of the following compounds will not give $$+ve$$ chromyl chloride test?
  • $$CuCl_2$$
  • $$HgCl_2$$
  • $$ZnCl_2$$
  • $$C_6H_5NH_{2}HCl$$
Which of these ions is expected to be coloured in aqueous solution?
I. $${Fe}^{3+}$$
II. $${Ni}^{2+}$$
III. $${Al}^{3+}$$
  • I and II
  • II and III
  • I and III
  • I, II and III
Which metal oxide is used to obtain blue coloured glass?
  • Ferric oxide
  • Chromium oxide
  • Manganese oxide
  • Cobalt oxide
Which of the following is true regarding derivation of the name of californium?
  • The name of californium was derived from the name of the place.
  • The name of californium was derived from its color.
  • The name of californium was derived from the name of the scientist who discovered it.
  • The name of californium was derived from mythological character name.
The only radioactive element among the lanthanoids is:
  • gadolinium
  • holmium
  • promethium
  • neodynium
Which of the following weights less when weighted in magnetic field?
  • $$Sr{ Cl }_{ 3 }$$
  • $$Fe{ Cl }_{ 3 }$$
  • $$Ti{ Cl }_{ 3 }$$
  • $$V{ Cl }_{ 3 }$$
Which of following ion has the maximum theoretical magnetic moment?
  • $$Cr^{3+}$$
  • $$Fe^{3+}$$
  • $$Ti^{3+}$$
  • $$Co^{3+}$$
Which lanthanide compound is used as a pigment?
  • $$CeO_{2}$$
  • $$Ce(OH)_{3}$$
  • $$Lu(OH)_{3}$$$
  • $$Tb(OH)_{3}$$
Which one of the following forms a colourless solution in an aqueous medium?

[Atomic number $$Sc=21, Ti=22, V=23, Cr=24$$]
  • $${ V }^{ 3+ }$$
  • $${ Cr }^{ 3+ }$$
  • $${ Ti }^{ 3+ }$$
  • $${ Sc }^{ 3+ }$$
The magnetic nature of elements depends on the presence of unpaired electrons. Identify the configuration of transition elements which shows highest magnetic moment?
  • $$3d^2$$
  • $$3d^8$$
  • $$3d^7$$
  • $$3d^5$$
How is sodium chromate converted into sodium dichromate in the manufacture of potassium dichromate from chromite ore?
  • By the action of concentrated sulphuric acid
  • By roasting with soda ash
  • By the action of sodium hydroxide
  • By the action of lime stone
The basic character of the transition metal monoxides follows the 
(At. no. of $$Ti=22,V=23,Cr=24,Fe=26$$)
  • $$TiO> VO> CrO> FeO$$
  • $$VO> CrO> TiO> FeO$$
  • $$CrO> VO> FeO> TiO$$
  • $$TiO> FeO> VO> CrO$$
Metals are usually used as catalysts belong to:
  • s-block
  • p-block
  • d-block
  • f-block
Identify the metal that forms colourless compounds.
  • Iron (Z = 26)
  • Chromium (Z = 24)
  • Vanadium (Z = 23)
  • Scandium (Z = 21)
Select the coloured compound amongst the following:

(Atomic no. $$Ti = 22, Cr = 24, Cu = 29, Zn = 30$$)
  • $$TiCl_4$$
  • $$CrCl_3$$
  • $$ZnCl_2$$
  • $$CuCl$$
Identify a 'Chemical twin' among the followings.
  • $$Zr-Ta$$
  • $$Nb-Tc$$
  • $$Hf-Re$$
  • $$Nb-Ta$$
Spin only magnetic moment value of $${ Cr }^{ 3+ }$$ ion is:
  • $$2.87$$ BM
  • $$3.87$$ BM
  • $$3.47$$ BM
  • $$3.67$$ BM
What is the atomic number of the element with $$M^{2+}$$ ion having electronic configuration $$[Ar]3d^{8}$$?
  • $$25$$
  • $$28$$
  • $$27$$
  • $$26$$
Select the coloured and paramagnetic ions.
  • $$Cu^+, Zn^{2+}, Ca^{2+}$$
  • $$Sc^{3+}, Ti^{4+}, V^{5+}$$
  • $$Cu^{2+}, Cr^+, Mn^{2+}$$
  • $$Ni^{2+}, Cu^+, Hg^{2+}$$
Experimental value of magnetic momentum of $${ Mn }^{ 2+ }$$ complex is $$5.96$$ B.M. This indicates:
  • Axial and orbital motion of electron in same direction
  • Axial and orbital motion of electron in opposite direction
  • Electron does not exhibit orbital motion, it only exhibits axial motion
  • Electron does not exhibit axial motion, it only exhibits orbital motion
The highest magnetic moment is shown by the transition metal ion with outer electronic configuration:
  • $${ d }^{ 9 }$$
  • $${ d }^{ 7 }$$
  • $${ d }^{ 5 }$$
  • $${ d }^{ 3 }$$
Ammonia will not form complex with:
  • $${ Ag }^{ 2+ }$$
  • $${ Pb }^{ 2+ }$$
  • $${ Cu }^{ 2+ }$$
  • $${ Cd }^{ 2+ }$$
There are $$14$$ elements in actinoid series. Which of the following elements does not belong to this series?
  • $$U$$
  • $$Np$$
  • $$Tm$$
  • $$Fm$$
Due to lanthanide contraction :
  • $$Fe, Co, Ni$$ have equal size
  • $$Zr$$ and $$Hf$$ have equal size
  • all $$ f-$$block ions have equal size
  • all isoelectronic ions have equal size
Generally transition elements for coloured salts due to the presence of unpaired electrons. Which of the following compound will be coloured in solid state? 
  • $$Ag_2SO_4$$
  • $$CuF_2$$
  • $$Cu_2Cl_2$$
  • $$ZnF_2$$
Which of the following ions has a magnetic moment of 5.93 BM?

[At . No. : V = 23 , Cr = 24, Mn = 25, Fe = 26]
  • $$Mn^{2+} $$
  • $$Fe^{2+}$$
  • $$Cr^{2+}$$
  • $$ V^{3+} $$
The type of magnetism exhibited by $$[Mn(H_2O)_6]^{2+}$$ ion is:
  • paramagnetism
  • diamagnetism
  • both (a) and (b)
  • none of these
Which of the following compound is expected to be coloured?
  • $$Ag_2SO_4$$
  • $$CuF_2$$
  • $$MgF_2$$
  • CuCl
The spin only magnetic moment of $$Fe^{3+}$$ ion (in BM) is approximately:
  • 4
  • 7
  • 5
  • 6
Magnetic moment of $$[Cu(NH_3)_4]^{2+}$$ ion is?
  • 1.414
  • 1.73
  • 2.23
  • 2.38
Which of the following is paramagnetic in nature? 
  • $$V(CO)_6$$
  • $$FeCO_5$$
  • $$Fe_2(CO)_9$$
  • $$Cr(CO)_6$$
Metallic radii of some transition elements are given below. Which of these elements will have the highest density?
Element                    $$Fe$$     $$CO$$       $$Ni$$     $$Cu$$ 
Metallic radii/pm     126     125     125    128
  • same 
  • $$Ni$$
  • $$Co$$
  • $$Cu$$
Which of the following arrangement does not represent the correct order of property stated against it ? 
  • $$V^{2+} < Cr^{3+} < Mn^{2+} < Fe^{2+} $$ : Paramagnetic behaviour
  • $$Ni^{2+} < Co^{2+} < Fe^{2+} < Mn^{2+}$$ Ionic size
  • $$Co^{3+} < Fe^{3+} , Cr^{3+} < Sc^{3+} $$: Stability in aqueous solution
  • $$Sc < Ti < Cr < Mn$$ : Number of oxidation states
Which of the following example is not correctly matched?
  • Two most abundant element -Fe, Al.
  • Two metals which occur in native state -Au, Pt.
  • Two metals which can occur in combined and native state both - Zn, Fe.
  • None of these.
Some compounds turn dark when exposed to light. They are, therefore, used in photography. A metal used for making such compounds is:
  • aluminium
  • nickel
  • chromium
  • silver
Magnetic moment of $${ x }^{ n+ }$$ is $$\sqrt { 24 }$$ B.M. Hence No. of unpaired electron and value of n is _____ respectively.
(Atomic number =26)
  • 4, 3
  • 3, 5
  • 4, 2
  • 4, 1
Generally metal iron and their salts are coloured due to presence of unpaired electrons in metal ions. Which of the following compounds are coloured?
  • $$Ce(SO_{4})_{2}$$
  • $$TiCl_{4}$$
  • $$Cu_{2}Cl_{2}$$
  • None of these
When $$MnO_{2}$$ is fused with KOH in the presence of air, a coloured compound is formed, the product and its colour is :
  • $$K_{2}MnO_{4}$$, dark green
  • $$KMnO_{4}$$, purple
  • $$Mn_{2}O_{3}$$, brown
  • $$Mn_{3}O_{4}$$, black.
Which of the following reactions are disproportionation reactions?
(I) $$Cu^+ \, \rightarrow \,  Cu^{2+} \, + \, Cu$$
(II) $$\displaystyle 3Mn{ O }{_{4}{^-}} \, + \, 4H^+ \, \rightarrow \,  2Mn{ O }{_{4}^{-}} \, + \, MnO_2 \, + \, 2H_2O$$
(III) $$2KMnO_4 \, \rightarrow \,  K_2MnO_4 \, + \, MnO_2 \, + \, O_2$$
(IV) $$2Mn{ O }{_{4}{^-}} \, + \, 3Mn^{2+} \, + \, 2H_2O \, \rightarrow \, 5MnO_2 \, + 4H{^+}$$
  • (I), (II)
  • (I), (II), (III)
  • (II), (III), (IV)
  • (I), (IV)
There are 14 elements in actinoid series. Which of the following elements does not belong to this series?
  • $$U$$
  • $$Np$$
  • $$Tm$$
  • $$Pm$$
When $$KMnO_4$$ solution is added to oxalic acid solution, the decolourisation is slow in the beginning but becomes instantaneous after some time because:
  • $$CO_2$$ is formed as the product
  • reaction is exothermic
  • $$Mn{ O }_{4}^{-}$$ catalyses the reaction
  • $$Mn^{2+}$$ acts as autocatalyst
Zr and Hf have almost equal atomic and ionic radii because of:
  • diagonal relationship.
  • lanthanoid contraction.
  • actinoid contraction.
  • belonging to the same group.
Due to lanthanoid contraction which of the following properties is not expected to be similar in the same vertical columns of second and third row transition elements?
  • Atomic radii
  • Ionisation energies
  • Magnetic moments
  • Lattice energies
0:0:1


Answered Not Answered Not Visited Correct : 0 Incorrect : 0

Practice Class 12 Engineering Chemistry Quiz Questions and Answers