p-Block Elements · JEE Main previous year questions

2005 8 questions

1. Q1702005 · 28 Apr 2005 · Shift 1

   2-methylbutane on reacting with bromine in the presence of sunlight gives mainly

   1. A.1-bromo-2-methylbutane
   2. B.2-bromo-2-methylbutane
   3. C.2-bromo-3-methylbutane
   4. D.1-bromo-3-methylbutane
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   Answer: B

2. Q1942005 · 28 Apr 2005 · Shift 1

   Elimination of bromine from 2-bromobutane results in the formation of-

   1. A.equimolar mixture of 1 and 2-butene
   2. B.predominantly 2-butene
   3. C.predominantly 1-butene
   4. D.predominantly 2-butyne
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   Answer: B

3. Q2002005 · 28 Apr 2005 · Shift 1

   An organic compound having molecular mass 60 is found to contain $\mathrm{C}=20\%$, $\mathrm{H}=6.67\%$ and $\mathrm{N}=46.67\%$ while rest is oxygen. On heating it gives $\mathrm{N}{\mathrm{H}}_3$ along with a solid residue. The solid residue give violet colour with alkaline copper sulphate solution. The compound is

   1. A.$\mathrm{C}{\mathrm{H}}_3\mathrm{NCO}$
   2. B.$\mathrm{C}{\mathrm{H}}_3\mathrm{CON}{\mathrm{H}}_2$
   3. C.$(\mathrm{N}{\mathrm{H}}_2{)}_2\mathrm{CO}$
   4. D.$\mathrm{C}{\mathrm{H}}_3\mathrm{C}{\mathrm{H}}_2\mathrm{CON}{\mathrm{H}}_2$
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   Answer: C

4. Q2092005 · 28 Apr 2005 · Shift 1

   The molecular shapes of $\mathrm{S}{\mathrm{F}}_4$, $\mathrm{C}{\mathrm{F}}_4$ and $\mathrm{Xe}{\mathrm{F}}_4$ are

   1. A.the same with 2,0 and 1 lone pairs of electrons on the central atom, respectively
   2. B.the same with 1, 1 and 1 lone pair of electrons on the central atoms, respectively
   3. C.different with 0, 1 and 2 lone pair of electrons on the central atoms, respectively
   4. D.different with 1, 0 and 2 lone pairs of electron on the central atoms respectively
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   Answer: D

5. Q2182005 · 28 Apr 2005 · Shift 1

   The number of hydrogen atom(s) attached to phosphorus atom in hypophosphorous acid is :

   1. A.zero
   2. B.two
   3. C.one
   4. D.three
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   Answer: B

6. Q2202005 · 28 Apr 2005 · Shift 1

   Heating an aqueous solution of aluminium chloride to dryness will give :

   1. A.$\mathrm{AlC}{\mathrm{l}}_3$
   2. B.$\mathrm{A}{\mathrm{l}}_2\mathrm{C}{\mathrm{l}}_6$
   3. C.$\mathrm{A}{\mathrm{l}}_2{\mathrm{O}}_3$
   4. D.$\mathrm{Al}(\mathrm{OH})\mathrm{C}{\mathrm{l}}_2$
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   Answer: C

7. Q2212005 · 28 Apr 2005 · Shift 1

   In silicon dioxide :

   1. A.Each silicon atom is surrounded by four oxygen atoms and each oxygen atom is bonded to two silicon atoms
   2. B.Each silicon atom is surrounded by two oxygen atoms and each oxygen atom is bonded to two silicon atoms
   3. C.Silicon atoms is bonded to two oxygen atoms
   4. D.there are double bonds between silicon and oxygen atoms
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   Answer: A

8. Q2222005 · 28 Apr 2005 · Shift 1

   The structure of diborane (${\mathrm{B}}_2{\mathrm{H}}_6$) contains :

   1. A.four 2c-2e bonds and two 3c-2e bonds
   2. B.two 2c-2e bonds and four 3c-2e bonds
   3. C.two 2c-2e bonds and two 3c-3e bonds
   4. D.four 2c-2e bonds and four 3c-2e bonds
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   Answer: A