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

2005 5 questions

1. Q1852005 · 28 Apr 2005 · Shift 1

   The lanthanide contraction is responsible for the fact that :

   1. A.Zr and Y have about the same radius
   2. B.Zr and Nb have similar oxidation state
   3. C.Zr and Hf have about the same radius
   4. D.Zr and Zn have the same oxidation
   Show answer

   Answer: C

2. Q1862005 · 28 Apr 2005 · Shift 1

   Which of the following factors may be regarded as the main cause of lanthanide contraction?

   1. A.Poor shielding of one of 4f electron by another in the subshell
   2. B.Effective shielding of one of 4f electrons by another in the subshell
   3. C.Poorer shielding of 5d electrons by 4f electrons
   4. D.Greater shielding of 5d electrons by 4f electrons
   Show answer

   Answer: A

3. Q1902005 · 28 Apr 2005 · Shift 1

   The value of the 'spin only' magnetic moment for one of the following configurations is $2.84\mathrm{BM}$. The correct one is :

   1. A.$d^4$ (in strong ligand field)
   2. B.$d^4$ (in weak ligand field)
   3. C.$d^3$ (in weak as well as in strong fields)
   4. D.$d^5$ (in strong ligand field)
   Show answer

   Answer: A

4. Q1932005 · 28 Apr 2005 · Shift 1

   Alkyl halides react with dialkyl copper reagents to give

   1. A.alkenes
   2. B.alkyl copper halides
   3. C.alkanes
   4. D.alkenyl halides
   Show answer

   Answer: C

5. Q2062005 · 28 Apr 2005 · Shift 1

   The oxidation state of chromium in the final product formed the reaction between $KI$ and acidified potassium dichromate solution is :

   1. A.$+3$
   2. B.$+2$
   3. C.$+6$
   4. D.$+4$
   Show answer

   Answer: A