d- and f-Block Elements · JEE Main previous year questions

2004 3 questions

1. Q1922004 · 24 Apr 2004 · Shift 1

   Cerium (Z = 58) is an important member of the lanthanoids. Which of the following statements about cerium is incorrect?

   1. A.The common oxidation states of cerium are +3 and +4
   2. B.Cerium (IV) acts as an oxidizing agent
   3. C.The +4 oxidation state of cerium is not known in solutions
   4. D.The +3 oxidation state of cerium is more stable than the +4 oxidation state
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   Answer: C

2. Q1972004 · 24 Apr 2004 · Shift 1

   The correct order of magnetic moments (spin only values in B.M.) among is : (Atomic numbers: Mn = 25; Fe = 26, Co =27)

   1. A.$[\mathrm{MnC}{\mathrm{l}}_4{]}^{2-}>[\mathrm{CoC}{\mathrm{l}}_4{]}^{-2}>[\mathrm{Fe}(\mathrm{CN}{)}_6{]}^{-4}$
   2. B.$[\mathrm{Fe}(\mathrm{CN}{)}_6{]}^{-4}>[\mathrm{CoC}{\mathrm{l}}_4{]}^{2-}>[\mathrm{MnC}{\mathrm{l}}_4{]}^{2-}$
   3. C.$[\mathrm{Fe}(\mathrm{CN}{)}_6{]}^{4-}>[\mathrm{MnC}{\mathrm{l}}_4{]}^{2-}>[\mathrm{CoC}{\mathrm{l}}_4{]}^{2-}$
   4. D.$[\mathrm{MnC}{\mathrm{l}}_4{]}^{2-}>[\mathrm{Fe}(\mathrm{CN}{)}_6{]}^{4-}>[\mathrm{CoC}{\mathrm{l}}_4{]}^{2-}$
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   Answer: A

3. Q2022004 · 24 Apr 2004 · Shift 1

   Which one of the following is reduced with zinc and hydrochloric acid to give the corresponding hydrocarbon?

   1. A.Ethyl acetate
   2. B.Butan-2-one
   3. C.Acetamide
   4. D.Acetic acid
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   Answer: B