Chemistry Term 2 - Delhi Set 3 2021-2022 Science (English Medium) Class 12 Question Paper Solution

Explain the following reactions:

Wolff Kishner reduction

Explain the following reaction:

Cannizzaro reaction

Arrange the following in the increasing order of the property mentioned:

\[\ce{CH3COOH, ClCH2COOH, FCH2COOH}\] (Acid strength)

Arrange the following in the increasing order of the property mentioned:

\[\ce{CH3CHO, CH3CH2OH, CH3CH2CH3}\] (Boiling Points).

Identify the order of reaction from the following unit for its rate constant:

L mol^–1s^–1

The conversion of molecules A to B follow second order kinetics. If concentration of A is increased to three times, how will it affect the rate of formation of B?

Write the expression of integrated rate equation for zero order reaction.

Account for the following:

pK_b of aniline is more than that of methylamine.

Account for the following:

Aniline does not undergo Friedel-Crafts reaction.

Account for the following:

Primary amines have higher boiling points than tertiary amines.

Arrange the following in increasing order of their basic strength in aqueous solution:

\[\ce{CH3NH2, (CH3)3N, (CH3)2NH}\]

What is Hinsberg's reagent?

What is the role of pyridine in the acylation reaction of amines?

Write the IUPAC name of the following complex:

\[\ce{K3[Cr(C2O4)3]}\]

On the basis of crystal field theory, write the electronic configuration for the d⁵ ion with a weak ligand for which Δ₀ < P.

What are ambidentate ligands?

Write any two consequences of Lanthanoid Contraction.

Name the element of 3d series which exhibits the largest number of oxidation states. Give reason.

Observe the graph shown in figure and answer the following questions:

1. What is the order of the reaction?
2. What is the slope of the curve?
3. Write the relationship between k and t_1/2 (half life period).

Give reasons for the following statement:

Transition elements and their compounds act as good catalysts.

Give reasons for the following statement:

\[\ce{E^0_{(Mn^{2+}/Mn)}}\] value is highly negative as compared to other elements.

Account for the following: 

Cr²⁺ is a strong reducing agent.

Define coagulation.

State Hardy-Schulze rule.

What is Electrophoresis?

Write three differences between Physisorption and Chemisorption.

An aromatic compound ‘A’ (C₇H₆O₂) on reaction with aqueous ammonia and heating forms compound ‘B’. ‘B’ on heating with Br₂ and alcoholic potash forms a compound ‘C’ of molecular formula C₆H₇N. Write the reactions involved and identify ‘A’, ‘B’, ‘C. 

A compound 'A' on reduction with iron scrap and hydrochloric acid gives compound 'B' with molecular formula C₆H₇N. Compound 'B' on reaction with CHCl₃ and alcoholic KOH produces an obnoxious smell of carbylamine due to the formation of 'C'. Identify 'A', 'B' and 'C' and write the chemical reactions involved.

Complete the following:

\[\ce{CH3CN ->[1. AlH(i - Bu)2][2. H2O] 'A' ->[H2N-OH][H^+] 'B'}\]

Write IUPAC name of the following compound:

Write chemical test to distinguish between the following compounds:

Phenol and Benzoic acid

Convert the following:

Benzoic acid to Benzaldehyde

Convert the following:

Propan-1-ol to 2-Bromopropanoic acid

Convert the following:

Acetaldehyde to But-2-enal

Read the passage given below and answer the questions that follow:

1. Is silver plate the anode or cathode?  (1)
2. What will happen if the salt bridge is removed?  (1)
3. When does electrochemical cell behaves like an electrolytic cell?  (1)
4. (i) What will happen to the concentration of Zn²⁺ and Ag⁺ when E_cell = 0.   (1)
   (ii) Why does conductivity of a solution decreases with dilution?  (1)
   OR
   The molar conductivity of a 1.5 M solution of an electrolyte is found to be 138.9 S cm²mol^-1. Calculate the conductivity of this solution.  (2)