CBSE Class 12 Biology Question Paper 2017 with Answer Key (April 5, Set 1 - 57/2/1)

CBSE CLASS XII Questions

• 1.

  Give structures of A, B and C: Aniline $\xrightarrow{Br_2/H_2O}$ A $\xrightarrow{NaNO_2+HCl, 0-5^\circ C}$ B $\xrightarrow{H_3PO_2+H_2O}$ C

  View Solution

  ---

• 2.

  Explain: (i) Presence of carbonyl group in glucose. (ii) Presence of five $-$OH groups attached to different carbon atoms.

  View Solution

  ---

• 3.

  Though chlorine shows strong $-I$ effect, why is it ortho/para directing?

  View Solution

  ---

• 4.

  For decomposition of $H_2O_2$ by $I^-$: Step I: $H_2O_2 + I^- \rightarrow H_2O + IO^-$ (slow). Step II: $H_2O_2 + IO^- \rightarrow H_2O + I^- + O_2$ (fast). (a) Write rate law. (b) Determine order w.r.t. $H_2O_2$ and $I^-$ and overall order. (c) Molecularity of Step II.

  View Solution

  ---

• 5.

  61 g benzoic acid (M = 122 g mol$^{-1}$) dissolved in 500 g benzene. Vapour pressure of pure benzene = 66 torr. Assume complete dimerisation. Calculate vapour pressure of solution.

  View Solution

  ---

• 6.

  Which isomer of $C_4H_9Br$ is most reactive towards $S_N1$ reaction?

  View Solution