JEE Chemistry The D and F Block Elements MCQs Set B

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 (iv)
• b) (ii) and (iv)
• c) (i) and (iii)
• d) (ii) and (iii)

Answer: (i) and (iv)

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) Ti³⁺
• c) Fe²⁺
• d) Mn²⁺

Answer: Sc³⁺

Question: Transition elements form coloured ions due to

• a) d-d transition
• b) smaller atomic radii
• c) fully filled d-orbitals
• d) availability of s-electrons

Answer: d-d transition

Question: The catalytic activity of transition metals and their compounds is mainly due to

• a) their ability to adopt variable oxidation state
• b) their chemical reactivity
• c) their unfilled d-orbitals
• d) their magnetic behaviour

Answer: their ability to adopt variable oxidation state

Question: Which of the following is colourless in water?

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

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

Answer: (i), (iii), (iv)

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: They are chemically reactive

Question: Formation of interstitial compound makes the transition metal

• a) more hard
• b) more ductile
• c) more soft
• d) more metallic

Answer: more hard

Question: If a non metal is added to the interstital sites of a metal, then the metal becomes

• a) less malleable
• b) softer
• c) less tensile
• d) more ductile

Answer: less malleable

Question:  Gun metal is an alloy of

• a) Cu, Zn and Sn
• b) Cu and Al
• c) Cu and Sn
• d) Cu, Zn and Ni

Answer: Cu, Zn and Sn

Question: Brass is an alloy of

• a) Zn and Cu
• b) Cu and Sn
• c) Zn and Sn
• d) Cu, Zn and Sn

Answer: Zn and Cu

Question: Which one of the following is coinage metal ?

• a) Cu
• b) Pb.
• c) Zn
• d) Sn

Answer: Cu

Question: Bronze is an alloy of

• a) Cu + Sn
• b) Cu + Zn
• c) Pb + Sn + Zn
• d) Pb + Zn

Answer: Cu + Sn

Question: An alloy of transition metal containing a non transition metal as a constituent is

• a) bronze
• b) stainless steel
• c) invar
• d) chrome steel

Answer: bronze

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

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

Answer: only (ii)

Question: Which of the following transition metal ion is colourless in queous solution?

• a) Both
• b) Zn²⁺
• c) Ti⁴⁺
• d) None of these

Answer: Both

Question: Transition metals show catalytic activity

• a) Both
• b) Due to their ability to show multiple oxidation state
• c) Due to their ability to form complexes
• d) None of these

Answer:  Both

Question: Which of the following transition metal on catalysis the reaction between iodide and persulphate ion?

• a) Fe³⁺
• b) Fe²⁺
• c) Ni²⁺
• d) None of these

Answer: Fe³⁺

Question:

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

Answer: (i) and (ii)

Question:

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

Answer: (ii) and (iii)

Question: K₂Cr₂O₇ on heating with aqueous NaOH gives

• a)

  

• b)

  

• c)

  

• d) None of these

Answer:

Question: CrO₃ dissolves in aqueous NaOH to give

• a)

  

• b)

  

• c)

  

• d) None of these

Answer:

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) + 6
• c) + 2
• d) + 4

Answer: + 3

Question: The bonds present in the structure of dichromate ion are

• a) six equivalent Cr – O bonds and one Cr – O – Cr bond
• b) six equivalent Cr – O bonds and one Cr – Cr bond
• c) six equivalent Cr – O bonds and one O – O bond
• d) four equivalent Cr – O bonds only

Answer: six equivalent Cr – O bonds and one Cr – O – Cr bond

Question: Potassium dichromate when heated with concentrated sulphuric acid and a soluble chloride, gives brown-red vapours of

• a) CrO₂Cl₂
• b) Cr₂O₃
• c) CrCl₃
• d) None of these

Answer:  CrO₂Cl₂

Question: The acidic, basic or amphoteric nature of Mn₂O₇, V₂O₅ and CrO are respectively

• a) acidic, amphoteric and basic
• b) acidic, basic and amphoteric
• c) basic, amphoteric and acidic
• d) acidic, acidic and basic

Answer: acidic, amphoteric and basic

Question: Which of the following oxides of Cr is amphoteric

• a) CrO₂
• b) CrO₅
• c) Cr₂O₃
• d) None of these

Answer: CrO₂

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a) Sn³⁺
• b) Sn⁴⁺
• c) Sn
• d) None of these

Answer: Sn³⁺

Question: In neutral or faintly alkaline medium, thiosulphate is quantitatively oxidized by KMnO₄ to

• a)

  

• b)

  

• c)

  

• d) None of these

Answer:

Question:

• a) CO₂
• b) HCl
• c) KOH
• d) SO₂

Answer: CO₂

Question: In the laboratory, manganese (II) salt is oxidised to permanganate ion in aqueous solution by

• a) peroxy disulphate
• b) hydrogen peroxide
• c) conc. nitric acid
• d) dichromate

Answer: peroxy disulphate

Question: The starting material for the manufacture of KMnO₄ is

• a) pyrolusite
• b) magnatite
• c) manganite
• d) haematite

Answer: pyrolusite

Question: An explosion take place when conc. H₂SO₄ is added to KMnO₄. Which of the following is formed?

• a) Mn₂O₇
• b) MnSO₄
• c) MnO₂
• d) M₂O₃

Answer:  Mn₂O₇

Question: If KMnO₄ is reduced by oxalic acid in an acidic medium then oxidation number of Mn changes from

• a) +7 to +2
• b) 4 to 2
• c) 6 to 4
• d) 7 to 4

Answer: +7 to +2

Question: KMnO₄ acts as an oxidising agent in alkaline medium. When alkaline KMnO₄ is treated with KI, iodide ion is oxidised to

• a)

  

• b)

  

• c)

  

• d)  None of these

Answer:

Question:

• a) Mn³⁺ is more stable than Mn²⁺.
• b) Cr²⁺ is reducing in nature
• c) Copper does not give H₂ on reaction with dil. H₂SO₄.
• d) None of these

Answer: Mn³⁺ is more stable than Mn²⁺.

Question: Which of the following is most acidic?

• a) Mn₂O₇
• b) V₂O₅
• c) Fe₂O₃
• d) None of these

Answer: Mn₂O₇

Question: Which of the following is the use of potassium permanganate?

• a) All of these
• b) In analytical chemistry
• c) decolourisation of oils
• d) Bleaching of wool, cotton and silk fibers

Answer: All of these

Question: A series1 metal ion , M(II) aqueous solution react with the KI to form iodine and a precipitate is formed, this M(II) can be:

• a) Cu²⁺
• b) Zn²⁺
• c) Mn²⁺
• d) Ni²⁺

Answer: Cu²⁺

Question: Total number of inner transition elements in the periodic table is

• a) 28
• b) 10
• c) 14
• d) 30

Answer: 28

Question: The lanthanoide contraction is responsible for the fact that

• a) Zr and Hf have about the same radius
• b) Zr and Zn have the same oxidation state
• c) Zr and Nb have similar oxidation state
• d) Zr and Y have about the same radius

Answer:  Zr and Hf have about the same radius

Question: Which of the following ions will exhibit colour in aqueous solutions?

• a) Ti³⁺ (Z = 22)
• b) Sc³⁺ (Z = 21)
• c) La³⁺ (Z = 57)
• d) Lu³⁺ (Z = 71)

Answer: Ti³⁺ (Z = 22)

Question: Which one of the following elements shows maximum number of different oxidation states in its compounds?

• a) Am
• b) La
• c) Eu
• d) Gd

Answer: Am

Question:  Lanthanoids are

• a)

  

• b)

  

• c)

  

• d) None of these

Answer:

Question: Which of the following factors may be regarded as the main cause of lanthanoide contraction?

• a)

  

• b)

  

• c)

  

• d) None of these

Answer:

Question: Lanthanoid which has the smallest size in +3 state is

• a) Lu
• b) Er
• c) Tb
• d) Ce

Answer:  Lu

Question:

• a)

  

• b)

  

• c)

  

• d) it is just before Ce in the periodic table

Answer:

Question: reduction in atomic size with increase in atomic number is a characteristic of elements of

• a)

  

• b)

  

• c) radioactive series
• d) high atomic masses

Answer:

Question: Which of the following oxidation states is the most common among the lanthanoids?

• a) 3
• b) 2
• c) 4
• d) 5

Answer: 3

Question: Identify the incorrect statement among the following

• a)

  

• b)

  

• c) The chemistry of various lanthanoids is very similar
• d) None of these

Answer:

Question: In context of the lanthanoids, which of the following statements is not correct

• a)

  

• b) Because of similar properties the separation of lanthanoids is not easy
• c) All the members exhibit +3 oxidation state
• d) There is a gradual decrease in the radii of the members with increasing atomic number in the series

Answer:

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: Which of the following lanthanoid ions is diamagnetic ?

(At nos. Ce = 58, Sm = 62, Eu = 63, Yb = 70)

• a) Yb²⁺
• b) Sm²⁺
• c) Eu²⁺
• d) Ce²⁺

Answer: Yb²⁺

Question: Lanthanide contraction can be observed in

• a) Gd
• b) Lw
• c) At
• d) Ac

Answer: Gd

Question: The most common lanthanide is

• a) cerium
• b) plutonium
• c) samarium
• d) lanthanum

Answer: cerium

Question: The approximate percentage of iron in mischmetal is

• a) 5
• b) 20
• c) 10
• d) 50

Answer: 5

Question:  Non-lanthanide atom is

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: In which of the following lanthanides oxidation state +2 is most stable?

• a) Eu
• b) Dy
• c) Ce
• d) Tb

Answer: Eu

Question: Actinoides

• a) have variable valency
• b) have any short lived isotopes
• c) include element 104
• d) are all synthetic elements

Answer: have variable valency

Question: Which of the following exhibit only + 3 oxidation state ?

• a) Ac
• b) U
• c) Th
• d) Pa

Answer: Ac

Question: Larger number of oxidation states are exhibited by the actinoids than those by the lanthanoids, the main reason being

• a)

  

• b)

  

• c)

  

• d) None of these

Answer:

Question: The maximum oxidation state exhibited by actinide ions is

• a) +7
• b) +5
• c) +4
• d) +8

Answer: +7

Question: There are 14 elements in actinoid series. Which of the following elements does not belong to this series

• a) Tm
• b) U
• c) Fm
• d) Np

Answer: Tm