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: A

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: A

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: A

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

Answer: A

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: A

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: A

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

Answer: A

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

Answer: A

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

Answer: A

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: A

Question. Which of the following transition metal ion is colourless in queous solution?
(a) Both
(b) Zn²⁺
(c) Ti⁴⁺
(d) None of these

Answer: A

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: A

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: A

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: A

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: A

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: A

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: A

Question. Which of the following oxides of Cr is amphoteric
(a) CrO₂
(b) CrO₅
(c) Cr₂O₃
(d) None of these

Answer: A

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: A

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

Answer: A

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: A

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: A

Question. Which of the following is most acidic?
(a) Mn₂O₇
(b) V₂O₅
(c) Fe₂O₃
(d) None of these

Answer: A

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: A

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: A

Question. Total number of inner transition elements in the periodic table is
(a) 28
(b) 10
(c) 14
(d) 30

Answer: A

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: A

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: A

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: A

Question. Lanthanoid which has the smallest size in +3 state is
(a) Lu
(b) Er
(c) Tb
(d) Ce

Answer: A

Question. Which of the following oxidation states is the most common among the lanthanoids?
(a) 3
(b) 2
(c) 4
(d) 5

Answer: A

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: A

Question. Lanthanide contraction can be observed in
(a) Gd
(b) Lw
(c) At
(d) Ac

Answer: A

Question. The most common lanthanide is
(a) cerium
(b) plutonium
(c) samarium
(d) lanthanum

Answer: A

Question. The approximate percentage of iron in mischmetal is
(a) 5
(b) 20
(c) 10
(d) 50

Answer: A

Question. In which of the following lanthanides oxidation state +2 is most stable?
(a) Eu
(b) Dy
(c) Ce
(d) Tb

Answer: A

Question. Actinoides
(a) have variable valency
(b) have any short lived isotopes
(c) include element 104
(d) are all synthetic elements

Answer: A

Question. Which of the following exhibit only + 3 oxidation state ?
(a) Ac
(b) U
(c) Th
(d) Pa

Answer: A

Question. The maximum oxidation state exhibited by actinide ions is
(a) +7
(b) +5
(c) +4
(d) +8

Answer: A

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: A