Other Chemistry · JEE Main previous year questions

2010 7 questions

1. Q622010 · 25 Apr 2010 · Shift 1

   Ionisation energy of $\mathrm{H}{\mathrm{e}}^{+}$ is $19.6\times 10^{-18}\mathrm{J}\mathrm{ato}{\mathrm{m}}^{-1}$. The energy of the first stationary state ($n=1$) of $\mathrm{L}{\mathrm{i}}^{2+}$ is

   1. A.$4.41\times 10^{-16}\mathrm{J}\mathrm{ato}{\mathrm{m}}^{-1}$
   2. B.$-4.41\times 10^{-17}\mathrm{J}\mathrm{ato}{\mathrm{m}}^{-1}$
   3. C.$-2.2\times 10^{-15}\mathrm{J}\mathrm{ato}{\mathrm{m}}^{-1}$
   4. D.$8.82\times 10^{-17}\mathrm{J}\mathrm{ato}{\mathrm{m}}^{-1}$
   Show answer

   Answer: B

2. Q662010 · 25 Apr 2010 · Shift 1

   Three reactions involving ${\mathrm{H}}_2\mathrm{P}{\mathrm{O}}_4^{-}$ are given below : (i) ${\mathrm{H}}_3\mathrm{P}{\mathrm{O}}_4+{\mathrm{H}}_2\mathrm{O}\to {\mathrm{H}}_3{\mathrm{O}}^{+}+{\mathrm{H}}_2\mathrm{P}{\mathrm{O}}_4^{-}$ (ii) ${\mathrm{H}}_2\mathrm{P}{\mathrm{O}}_4^{-}+{\mathrm{H}}_2\mathrm{O}\to \mathrm{HP}{\mathrm{O}}_4^{2-}+{\mathrm{H}}_3{\mathrm{O}}^{+}$ (iii) ${\mathrm{H}}_2\mathrm{P}{\mathrm{O}}_4^{-}+\mathrm{O}{\mathrm{H}}^{-}\to {\mathrm{H}}_3\mathrm{P}{\mathrm{O}}_4+{\mathrm{O}}^{2-}$ In which of the above does ${\mathrm{H}}_2\mathrm{P}{\mathrm{O}}_4^{-}$ act as an acid?

   1. A.(ii) only
   2. B.(i) and (ii)
   3. C.(iii) only
   4. D.(i) only
   Show answer

   Answer: A

3. Q672010 · 25 Apr 2010 · Shift 1

   In aqueous solution the ionization constants for carbonic acid are ${\mathrm{K}}_1=4.2\times 10^{-7}$ and ${\mathrm{K}}_2=4.8\times 10^{-11}$ Select the correct statement for a saturated 0.034 M solution of the carbonic acid.

   1. A.The concentration of $\mathrm{C}{\mathrm{O}}_3^{2-}$ is 0.034 M.
   2. B.The concentration of $\mathrm{C}{\mathrm{O}}_3^{2-}$ is greater than that of $\mathrm{HC}{\mathrm{O}}_3^{-}$
   3. C.The concentration of ${\mathrm{H}}^{+}$ and $\mathrm{HC}{\mathrm{O}}_3^{-}$ are approximately equal.
   4. D.The concentration of ${\mathrm{H}}^{+}$ is double that of $\mathrm{C}{\mathrm{O}}_3^{2-}$.
   Show answer

   Answer: C

4. Q762010 · 25 Apr 2010 · Shift 1

   The correct order of $E_{M^{2+}/M}^o$ values with negative sign for the four successive elements Cr, Mn, Fe and Co is :

   1. A.$\mathrm{Mn}>\mathrm{Cr}>\mathrm{Fe}>\mathrm{Co}$
   2. B.$\mathrm{Cr}>\mathrm{Fe}>\mathrm{Mn}>\mathrm{Co}$
   3. C.$\mathrm{Fe}>\mathrm{Mn}>\mathrm{Cr}>\mathrm{Co}$
   4. D.$\mathrm{Cr}>\mathrm{Mn}>\mathrm{Fe}>\mathrm{Co}$
   Show answer

   Answer: A

5. Q832010 · 25 Apr 2010 · Shift 1

   Biuret test is not given by

   1. A.carbohydrates
   2. B.polypeptides
   3. C.urea
   4. D.proteins
   Show answer

   Answer: A

6. Q842010 · 25 Apr 2010 · Shift 1
   
   1. A.$B>C>A$
   2. B.$B>A>C$
   3. C.$C>B>A$
   4. D.$A>B>C$
   Show answer

   Answer: A

7. Q862010 · 25 Apr 2010 · Shift 1
   
   1. A.nitrobenzene and fluorobenzene
   2. B.phenol and benzene
   3. C.benzene diazonium chloride and fluorobenzene
   4. D.nitrobenzene and chlorobenzene
   Show answer

   Answer: C