CBSE Class 12 Biology (Blind) Question Paper 2015 with Answer Key (March 23, Set 4 - 57(B))

CBSE CLASS XII Questions

• 1.

  Predict the alkene formed by dehydrohalogenation of 1-Bromo-1-methylcyclohexane.

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• 2.

  Draw the structures of major products: (a) Chlorobenzene + $CH_3Cl$ / Na, dry ether
  (b) p-Hydroxyphenethyl alcohol + HBr

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• 3.

  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.

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• 4.

  Under what condition can a bimolecular reaction become kinetically first order?

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• 5.

  Why are magnesium blocks attached to iron water pipelines?

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• 6.

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

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