The The d – and f – Block Elements VBQs Class 12 Chemistry

VBQs for Class 12

VBQs The d – and f – Block Elements Class 12 Chemistry with The d – and f – Block Elements has been provided below for standard students. We have provided chapter wise VBQ for Class 12 Chemistry with The d – and f – Block Elements. The following The d – and f – Block Elements Class 12 Chemistry value based questions with answers will come in your exams. Students should understand the concepts and learn the solved cased based VBQs provided below. This will help you to get better marks in class 12 examinations.

The d – and f – Block Elements VBQs Class 12 Chemistry

Question. Which one of the following ions exhibit highest magnetic moment?
(a) Cu2+
(b) Ti3+
(c) Ni2+
(d) Mn2+

Answer

D

Question. Which of the following ions has the maximum magnetic moment?
(a) Mn+2
(b) Fe+2
(c) Ti3+
(d) Cr+2.

Answer

A

Question. Which of the following transition metal on catalysis the reaction between iodide and persulphate ion?
(a) Fe2+
(b) Fe3+
(c) Ni2+
(d) Both (a) and (c)

Answer

B

Question. Four successive members of the first row transition elements are listed below with atomic numbers. Which one of them is expected to have the highest E0 M3+ /M2+  value ?
(a) Cr(Z = 24)
(b) Mn(Z = 25)
(c) Fe(Z = 26)
(d) Co(Z = 27)

Answer

D

Question. If KMnO4 is reduced by oxalic acid in an acidic medium then oxidation number of Mn changes from
(a) 4 to 2
(b) 6 to 4
(c) +7 to +2
(d) 7 to 4

Answer

C

Question.Which of the following ions having following electronic structure would have maximum magnetic moment?
(a) 1s2 2s2 2p6 3s3 p63d 3
(b) 1s2 2s2p3s3p63d 5
(c) 1s2s2 2p6 3s3p63d7
(d) 1s2 2s22p6 3s3p63d 9

Answer

B

Question. If n is the number of unpaired electrons, the magnetic moment (in BM) of transition metal/ion is given by

The The d – and f – Block Elements VBQs Class 12 Chemistry
Answer

A

Question. Bronze is an alloy of
(a) Pb + Sn + Zn
(b) Cu + Sn
(c) Pb + Zn
(d) Cu + Zn

Answer

B

Question. The magnetic nature of elements depend on the presence of unpaired electrons. Identify the configuration of transition element, which shows highest magnetic moment.
(a) 3d7
(b) 3d 5
(c) 3d8
(d) 3d 2

Answer

B

Question. Which of the following transition metal ion is colourless in aqueous solution?
(a) Ti4+
(b) Zn2+
(c) V4+
(d) Both (a) and (b)

Answer

D

Question.The aqueous solution containing which one of the following ions will be colourless? (Atomic number:
Sc = 21, Fe = 26, Ti = 22, Mn = 25)
(a) Sc3+
(b) Fe2+
(c) Ti3+
(d) Mn2+

Answer

A

Question. Transition elements form coloured ions due to
(a) d-d transition
(b) fully filled d-orbitals
(c) smaller atomic radii
(d) availability of s-electrons

Answer

A

Question. KMnO4 can be prepared from K2MnO4 as per the reaction:
3MnO42- +2H2O ⇌  2MnO42- +MnO2 + 4OH
The reaction can go to completion by removing OH– ions by adding.
(a) KOH
(b) CO2
(c) SO2
(d) HCl

Answer

B

Question. The catalytic activity of transition metals and their compounds is mainly due to
(a) their magnetic behaviour
(b) their unfilled d-orbitals
(c) their ability to adopt variable oxidation state
(d) their chemical reactivity

Answer

C

Question. KMnO4 acts as an oxidising agent in alkaline medium. When alkaline KMnO4 is treated with KI, iodide ion is oxidised to________ .
(a) I2
(b) IO
(c) IO3
(d) IO4

Answer

A

Question. Formation of interstitial compound makes the transition metal
(a) more soft
(b) more ductile
(c) more metallic
(d) more hard

Answer

D

Question. Which one of the following ions has the maximum magnetic moment?
(a) Sc3+
(b) Ti3+
(c) Cr3+
(d) Fe3+

Answer

D

Question. Gun metal is an alloy of
(a) Cu and Al
(b) Cu and Sn
(c) Cu, Zn and Sn
(d) Cu, Zn and Ni

Answer

C

Question. What is wrong about transition metals?
(a) Diamagnetic
(b) Paramagnetic
(c) Form complexes
(d) Shows variable oxidation state

Answer

A

Question. When acidified K2Cr2O7 solution is added to Sn2+ salts then Sn2+ changes to
(a) Sn
(b) Sn3+
(c) Sn4+
(d) Sn+

Answer

C

Question.  The starting material for the manufacture of KMnO4 is
(a) pyrolusite
(b) manganite
(c) magnatite
(d) haematite

Answer

A

Question. An alloy of transition metal containing a non transition metal as a constituent is
(a) invar
(b) bronze
(c) chrome steel
(d) stainless steel

Answer

B

Question. Choose the correct increasing order of the oxidation state of the central metal atom in the following oxoanions.

The The d – and f – Block Elements VBQs Class 12 Chemistry
Answer

B

Question. Titanium shows magnetic moment of 1.73 B.M. in its compound. What is the oxidation number of Ti in the compound?
(a) +1
(b) +4
(c) +3
(d) +2

Answer

C

Question. Which of the following ion(s) is/are oxidising in nature?

The The d – and f – Block Elements VBQs Class 12 Chemistry

(a) (i) and (iii)
(b) only (ii)
(c) (ii) and (iii)
(d) only (iii)

Answer

B

Question. Transition metals show catalytic activity
(a) Due to their ability to form complexes.
(b) Due to their ability to show multiple oxidation state.
(c) Due to availabiltiy of d orbitals for bond formation.
(d) Both (a) and (b).

Answer

D

Question. Which of the following is the use of potassium permanganate?
(a) Bleaching of wool, cotton and silk fibers.
(b) decolourisation of oils.
(c) In analytical chemistry.
(d) All of these.

Answer

D

Question. Which of the following reactions are disproportionation reactions ?

The The d – and f – Block Elements VBQs Class 12 Chemistry

(a) (i) and (ii)
(b) (i), (ii) and (iii)
(c) (ii), (iii) and (iv)
(d) (i) and (iv)

Answer

A

Question.  Which one of the following is coinage metal ?
(a) Zn
(b) Cu
(c) Sn
(d) Pb.

Answer

B

Question. Which of the following is colourless in water?
(a) Ti3+
(b) V3+
(c) Cu3+
(d) Sc3+

Answer

D

Question. K2 on heating with aqueous NaOH gives
(a) Cr2O42-
(b) Cr(OH)3
(c) Cr2O72-
(d) Cr(OH)2

Answer

A

Question. A compound of a metal ion Mx+ (Z = 24) has a spin only magnetic moment of 15 Bohr Magnetons. The number of unpaired electrons in the compound are
(a) 2
(b) 4
(c) 5
(d) 3

Answer

D

Question. The oxidation state of chromium in the final product formed by the reaction between KI and acidified potassium dichromate solution is
(a) + 3
(b) + 2
(c) + 6
(d) + 4

Answer

A

Question. The bonds present in the structure of dichromate ion are
(a) four equivalent Cr – O bonds only
(b) six equivalent Cr – O bonds and one O – O bond
(c) six equivalent Cr – O bonds and one Cr – Cr bond
(d) six equivalent Cr – O bonds and one Cr – O – Cr bond

Answer

D

Question. If a non metal is added to the interstital sites of a metal, then the metal becomes
(a) softer
(b) less tensile
(c) less malleable
(d) more ductile

Answer

C

Question. Transition elements show magnetic moment due to spin and orbital motion of electrons. Which of the following metallic ions have almost same spin only magnetic moment?
(i) Co2+
(ii) Cr2+
(iii) Mn2+
(iv) Cr3+
(a) (i) and (iii)
(b) (i) and (iv)
(c) (ii) and (iii)
(d) (ii) and (iv)

Answer

B

Question. Which of the following is amphoteric oxide ?
Mn2O7 ,CrO3,Cr2O3 ,CrO,V2O5,V2O4
(a) V2O5 , Cr2O3
(b) Mn2O7 , CrO3
(c) CrO, V2O5
(d) V2O5, V2O4

Answer

A

Question. Which of the following statements about the interstitial compounds is incorrect ?
(a) They are chemically reactive.
(b) They are much harder then the pure metal.
(c) They have higher melting points than the pure metal.
(d) They retain metallic conductivity.

Answer

A

Question. In neutral or faintly alkaline medium, thiosulphate is quantitatively oxidized by KMnOto
(a) SO32–
(b) SO42–
(c) SO2
(d) SO52–

Answer

B

Question. Potassium dichromate when heated with concentrated sulphuric acid and a soluble chloride, gives brown-red vapours of
(a) CrO3
(b) CrCl3
(c) CrO2Cl2
(d) Cr2O3

Answer

C

Question. In the laboratory, manganese (II) salt is oxidised to permanganate ion in aqueous solution by
(a) hydrogen peroxide
(b) conc. nitric acid
(c) peroxy disulphate
(d) dichromate

Answer

C

Question. CrO3 dissolves in aqueous NaOH to give
(a) Cr2O72–
(b) CrO42–
(c) Cr(OH)3
(d) Cr(OH)2

Answer

B

Question. Which of the following is most acidic?
(a) Mn2O7
(b) V2O5
(c) Fe2O3
(d) Cr2O3

Answer

A

Question. An explosion take place when conc. H2SO4 is added to KMnO4. Which of the following is formed?
(a) Mn2O7
(b) MnO2
(c) MnSO4
(d) M2O3

Answer

A

Question. The acidic, basic or amphoteric nature of Mn2O7, V2O5 and CrO are respectively
(a) acidic, acidic and basic
(b) basic, amphoteric and acidic
(c) acidic, amphoteric and basic
(d) acidic, basic and amphoteric

Answer

B

Question. In the form of dichromate, Cr (VI) is a strong oxidising agent in acidic medium but Mo (VI) in MoO3 and W (VI) in WO3 are not because ____________ .
(i) Cr (VI) is more stable than Mo(VI) and W (VI).
(ii) Mo (VI) and W(VI) are more stable than Cr(VI).
(iii) Higher oxidation states of heavier members of group- 6 of transition series are more stable.
(iv) Lower oxidation states of heavier members of group-6 of transition series are more stable.
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (i) and (iv)
(d) (ii) and (iv)

Answer

B

Question. On the basis of data given below,

The The d – and f – Block Elements VBQs Class 12 Chemistry

Which of the following statements is incorrect?
(a) Sc3+ has good stability due of [Ar]3d04s0 configuration.
(b) Mn3+ is more stable than Mn2+.
(c) Cr2+ is reducing in nature.
(d) Copper does not give H2 on reaction with dil. H2SO4.

Answer

A

Question. Brass is an alloy of
(a) Zn and Sn
(b) Zn and Cu
(c) Cu, Zn and Sn
(d) Cu and Sn

Answer

B

Question. Which group contains coloured ions out of
(i) Cu2+
(ii) Ti4+
(iii) Co2+
(iv) Fe2+
(a) (i), (ii), (iii), (iv)
(b) (i), (iii), (iv)
(c) (ii), (iii)
(d) (i), (ii)

Answer

B