CBSE Questions for Class 12 Engineering Chemistry The D-And F-Block Elements Quiz 14 - MCQExams.com

Transition metals show paramagnetic :
  • due to characteristic configuration
  • high lattice energy
  • due to variable oxidation states
  • due to unpaired electrons
Match List-I with List -II and select the correct answer using codes given ahead in the lists:
List-I
Metal ions
List-II
Magnetic moments (B.M)
$$Cr^{3+}$$$$\sqrt{35}$$
$$Fe^{2+}$$$$\sqrt{30}$$
$$Ni^{2+}$$$$\sqrt {24}$$
$$Mn^{2+}$$$$\sqrt{15}$$
$$\sqrt 8$$
  • $$A-1, B-3, C-5, D-4$$
  • $$A-2, B-3, C-5, D-1$$
  • $$A-4, B-3, C-5, D-1$$
  • $$A-4, B-5, C-3, D-1$$
Wilkinson's catalyst contains :
  • rhodium
  • iron
  • aluminium
  • cobalt
The catalysic activity of transition elements and their compounds is described to:
  • their chemical reactivity
  • their magnetic behaviour
  • their unfilled $$d-$$orbital
  • their ability to adopt multiple oxidation states and their complexing ability.
Select the correct statements :
  • Diamond is hard while graphite is soft and slippery
  • The degree of co valency in the following compounds runs as $$HgX_2 > CdX_2 > ZnX_2$$
  • $$ZnS$$ is white, $$CdS$$ is yellow, while $$HgS$$ is black
  • Diamond is soft while graphite is hard
Which of the following sulphides is yellow in colour?
  • $$CuS$$
  • $$CdS$$
  • $$ZnS$$
  • $$CoS$$
The statement that is not correct for the periodic classification of elements is: 
  • The properties of elements are the periodic function of their atomic numbers.
  • Non - metallic elements are lesser in number than metallic elements.
  • The first ionisation energies of elements along a period do not vary in a regular manner with increase in atomic number.
  • For transition elements the d subshells are filled with electrons monotonically with increase in atomic number.
Which of the following compounds is (are) coloured due to charge transfer spectra and not due to $$d-d$$ transition?
  • $$KMnO_4$$
  • $$K_2CrO_4$$
  • $$CrO_3$$
  • All of these
On heating chromite $$(FeCr_2O_4)$$ with $$Na_2CO_3$$ in air, the following product is obtained:
  • $$Na_2CrO_4$$
  • $$Na_2Cr_2O_7$$
  • $$FeO$$
  • $$Fe_3O_4$$
Number of moles of $$K_2Cr_2O_7$$ radius by $$1$$ mole of $$Sn^{2+}$$ is:
  • $$1/6$$
  • $$2/3$$
  • $$1/3$$
  • $$1$$
Which of the following are paramagnetic?
  • $$[Fe(CN)_6]^{4-}$$
  • $$Ni(CO)_4$$
  • $$[NiCl_4]^{2-}$$
  • $$[CoF_6]^{3-}$$
Predict the magnetic nature of $$A$$ and $$B$$:
  • Both are diamagnetic
  • Both are paramagnetic
  • $$A$$ is paramagnetic and $$B$$ is diamagnetic
  • $$A$$ is diamagnetic and $$B$$ is paramagnetic
Which of the following sulphides is yellow?
  • $$ZnS$$
  • $$CdS$$
  • $$NiS$$
  • $$PbS$$
Consider the following statements and arrange in the order of true/false as given in the codes.
$$S_{1}$$ : Both $$\left [ Co\left ( ox \right )_{3} \right ]^{3-}$$ and $$\left [ CoF_{6} \right ]^{3-}$$ are paramegnetic.
$$S_{2}:CoCl_{3}3NH_{3}$$ complex is non-conducing.
$$S_{3}$$ : The number of possible isomers for the complex $$\left [ Pt\left ( NO_{2} \right )\left ( py \right )\left ( OH \right )\left ( NH_{3} \right ) \right ]$$ is six.
$$S_{4}$$ : The oxidation state of iron in brown ring complex $$\left [ Fe\left ( H_{2}O \right )_{5}NO^{+} \right ]SO_{4}$$ is +II where NO is $$NO^{+}$$
  • F T T F
  • T T T T
  • F T T F
  • T T T F
Which of the following complexes is / are paramagnetic?
  • $$\left [ Mn\left ( CN_{6} \right ) \right ]^{3-}$$
  • $$\left [ Cr\left ( NH_{3} \right )_{6} \right ]^{3+}$$
  • $$\left [ Fe\left ( CN \right )_{6} \right ]^{4-}$$
  • $$\left [ Co\left ( CN \right )_{6} \right ]^{3-}$$
Which of the following statements is correct ? (I) Anions of both (B) and (C) are diamagnetic and have tetrahedral  geometry (II) Anions of both (B) and (C)  are paramagnetic and have tetrahedral geometry (III) Anions of (B) is paramagnetic and that of (C) is diamagnetic but both have  tetrahedral geometries (IV) Green coloured compound (B) in a neutral or acidic medium disproportionates  to give (C) and (D) 
  • I and II only
  • II and III only
  • II and IV only
  • III and IV only
Which of the following types of metal make the most efficient catalysts?
  • Alkali metal
  • Transition metal
  • Alkali-earth metals
  • Radioactive metals
Which of the following pair of compounds is expected to exhibit same colour in aqueous solution ? 
  • $$FeCl_{2},CuCl_{2}$$
  • $$VOCl_{2},CuCl_{2}$$
  • $$VOCl_{2},FeCl_{2}$$
  • $$FeCl_{2},MnCl_{2}$$
Titanium shows magnetic moment of 1.73 B M in its compound . What is the oxidation state of titanium in the compound ?  
  • +2
  • +1
  • +3
  • +4
Consider the following statements and arrange in the order of true/false as given in the codes.
$$S_{1}$$ : The IUPAC name of the compound $$\left [ Cr\left ( NH_{3} \right )_{5} \left ( NCS \right )\right ]\left [ ZnCl_{4} \right ]$$ is pentaamminethiocyanato-N-chromate (III) tetraachlorozincate (II).
$$S_{2}: CoSO_{4}$$ is paramagnetic and coloured.
$$S_{3}:\left [ Co\left ( NH_{3} \right )_{4}\left ( NO_{2} \right )_{2} \right ]NO_{3}$$ shows ionisation, linkage and geometrical isomerism.
$$S_{4}$$ : The C-O bond length in the complex, $$\left [ Fe\left ( CO \right )_{5} \right ]$$ is same as that found in carbon monoxide itself.
  • F T T F
  • T T T T
  • F T T F
  • T T T F
Fe, Co and Ni have valuable catalytic properties in process involving 
  • Organic compound
  • Oxidation
  • Hydrogenation
  • Compounds of hydrogen
Which has the maximum ferromagnetic character? 
  • Fe
  • Co
  • Ni
  • Pt
Which of the following may be colourless? 
  • $$ Cr^{3+} $$
  • $$ Cu^{+} $$
  • $$ Fe^{3+} $$
  • $$ Cu^{2+} $$
Which of the following species is expected to show the highest magnetic moment? (At. No.: Cr = 24, Mn = 25, Co = 27, Ni = 28, Cu =29)
  • $$ Cr^{2+} $$
  • $$ Mn^{2+} $$
  • $$ Cu^{2+} $$
  • $$ Co^{2+} $$
  • $$ Ni^{2+} $$
The 3d metal ions form coloured compounds because the energy corresponding to the following lies in the visible range of electromagnetic spectrum 
  • free energy change of complex formation by 3d metal ions
  • d-d transition of 3d electrons
  • heat of hydration of 3d metal ions
  • ionisation energy of 3d metal ions
Which one of the following characteristics of the transition metals is associated with their catalytic activity? 
  • Variable oxidation states
  • High enthalpy of atomization
  • Paramagnetic behaviour
  • Colour of hydrated ions
The magnetic moment of a metal ion of first transition series is 2.83 BM. Therefore it will have unpaired electrons 
  • 6
  • 4
  • 3
  • 2
Which of the following trivalent ion has the largest atomic radii in the lanthanide series?
  • $$ La $$
  • $$ Ce $$
  • $$ Pm $$
  • $$ Lu $$
A copper salt is isomorphic with $$ ZnSO_4 $$, the salt will be 
  • paramagnetic
  • diamagnetic
  • ferromagnetic
  • none
Effective magnetic moment of $$ Sc^{3+} $$ ion is 
  • 1.73
  • 0
  • 5.92
  • 2.83
  • 3.87
Which one of the following ions is colourless? 
  • $$ Cu^+ $$
  • $$ Co^{2+} $$
  • $$ Ni^{2+} $$
  • $$ Fe^{3+} $$
Which of the following ions has the highest magnetic moment?
  • $$ Ti^{3+} $$
  • $$ Sc^{3+} $$
  • $$ Mn^{2+} $$
  • $$ Zn^{2+} $$
Chloride of which of the following element is coloured? 
  • Ag
  • Hg
  • Zn
  • Co
In nitroprusside ion, the iron and $$NO$$ exist as $$ Fe^{II} $$  and $$ NO^+ $$ rather than $$ Fe^{III } $$ and $$ NO $$. These forms can be differentiated by 
  • Estimating the concentration of iron
  • Measuring the concentration of $$ CN^- $$
  • Measuring the solid state magnetic moment
  • Thermally decomposing the compound
On adding excess of $$ NH_3 $$ solution to $$ CuSO_4 $$ solution, the dark blue colour is due to  
  • $$ [ Cu(NH_3)_4] ^{2+} $$
  • $$ [ Cu(NH_3)_2]^{2+} $$
  • $$ [ Cu(NH_3)]^+ $$
  • None of the above
Which of the following pair will have effective magnetic moment equal?
  • $$ Cr^{3+} $$ and $$ Mn^{2+} $$
  • $$ Cr^{2+} $$ and $$ Fe^{2+} $$
  • $$ V^{2+} $$ and $$ Sc^{3+} $$
  • $$ Ti^{2+} $$ and $$ V^{2+} $$
On heating $$ Mn(OH)_2 $$ with $$ PbO_2 $$ and conc. $$ HNO_3 $$ pink colour is obtained due to the formation of 
  • $$ KMnO_4 $$
  • $$ HMnO_4 $$
  • $$ Pb(MnO_4 )_2 $$
  • $$ PbMnO_4 $$
Which of the following weighs less when weighed in magnetic field?
  • $$ VCl_3 $$
  • $$ ScCl_3 $$
  • $$ TiCl_3 $$
  • $$ FeCl_3 $$
Which of the following is more paramagnetic? 
  • $$ Fe^{2+} $$
  • $$ Fe^{3+} $$
  • $$ Cr^{3+} $$
  • $$ Mn^{3+} $$
Which of the following reagents can be used for the given reaction ?
1769561_d3278637c0214bcaab3f289780608c0f.png
  • $$i. D_2O / D_3O^\bigoplus \,ii. Cl_2 + AcOH \,iii. NaBH_4 / H_2O$$
  • $$i. Cl_2 + AcOH \,ii. D_2O \,iii. LAH / H_2O$$
  • $$ii. D_2O \,iii. HgCl_2 / CdCO_3 / H_2O$$
  • $$i. Base (PhLi), \,ii. HgCl_2 / CdCO_3-H_2O \, iii. D_2O$$
Pick out wrong combination
  • $$Fe^{+2}\rightarrow Haemoglobin$$
  • $$Mg^{2+}\rightarrow Photosynthesis$$
  • $$Se^{2+}\rightarrow Kreb \ Cycle$$
  • $$CO^{+2}\rightarrow Vitamin \ B-12$$
Which of the following has maximum magnetic moment?
  • $${V}^{3+}$$
  • $${Cr}^{3+}$$
  • $${Fe}^{3+}$$
  • $${C}^{3+}$$
Which of the following is diamagnetic?
  • $${Cu}^{2+}$$
  • $${Zn}^{2+}$$
  • $${Cr}^{2+}$$
  • $${Ti}^{2+}$$
Transition metals are not characterized by :
  • fixed valency
  • coloured compound
  • high melting and boiling points
  • tendency to form complexes
The calculated spin only magnetic moment of $$Cr^{2+}$$ ion is
  • $$4.90 BM$$
  • $$5.92 BM$$
  • $$2.84 BM$$
  • $$3.87 BM$$
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