p-Block Elements · JEE Main previous year questions

2004 4 questions

1. Q1492004 · 24 Apr 2004 · Shift 1

   The ammonia evolved from the treatment of 0.30 g of an organic compound for the estimation of nitrogen was passed in 100 mL of 0.1 M sulphuric acid. The excess of acid required 20 mL of 0.5 M sodium hydroxide solution for complete neutralization. The organic compound is

   1. A.urea
   2. B.benzamide
   3. C.acetamide
   4. D.thiourea
   Show answer

   Answer: A

2. Q1592004 · 24 Apr 2004 · Shift 1

   The states of hybridization of boron and oxygen atoms in boric acid (${\mathrm{H}}_3\mathrm{B}{\mathrm{O}}_3$) are respectively

   1. A.$\mathrm{s}{\mathrm{p}}^2$ and $\mathrm{s}{\mathrm{p}}^2$
   2. B.$\mathrm{s}{\mathrm{p}}^3$ and $\mathrm{s}{\mathrm{p}}^3$
   3. C.$\mathrm{s}{\mathrm{p}}^3$ and $\mathrm{s}{\mathrm{p}}^2$
   4. D.$\mathrm{s}{\mathrm{p}}^2$ and $\mathrm{s}{\mathrm{p}}^3$
   Show answer

   Answer: D

3. Q2172004 · 24 Apr 2004 · Shift 1

   Which among the following factors is the most important in making fluorine the strongest oxidizing halogen?

   1. A.Electron affinity
   2. B.Bond dissociation energy
   3. C.Hydration enthalpy
   4. D.Ionization enthalpy
   Show answer

   Answer: C

4. Q2182004 · 24 Apr 2004 · Shift 1

   Aluminium chloride exists as dimer, $\mathrm{A}{\mathrm{l}}_2\mathrm{C}{\mathrm{l}}_6$ in solid state as well as in solution of non-polar solvents such as benzene. When dissolved in water, it gives :

   1. A.$\mathrm{A}{\mathrm{l}}^{3+}+3C{\mathrm{l}}^{-}$
   2. B.$\mathrm{A}{\mathrm{l}}_2{\mathrm{O}}_3+6HCl$
   3. C.$[\mathrm{Al}(\mathrm{OH}{)}_6{]}^{3-}$
   4. D.$[\mathrm{Al}({\mathrm{H}}_2\mathrm{O}{)}_6{]}^{3+}+3C{\mathrm{l}}^{-}$
   Show answer

   Answer: D