Chemistry Delhi Set - 2 2023-2024 Science (English Medium) Class 12 Question Paper Solution

Which of the following species can act as the strongest base?

\[\ce{OH-}\]

\[\ce{C6H5O-}\]

\[\ce{RO-}\]

Auto-oxidation of chloroform in air and sunlight produces a poisonous gas known as ______.

Tear gas

Mustard gas

Phosgene gas

Chlorine gas

Phosphine 

Isotonic solutions have the same ______.

density 

refractive index

osmotic pressure

volume

The specific sequence in which amino acids are arranged in a protein is called its ______.

Primary structure

Secondary structure

Tertiary structure

Quaternary structure

Transition metals are known to make interstitial compounds. Formation of interstitial compounds makes the transition metal ______.

more hard

more soft

more ductile

more metallic

The correct name of the given reaction is:

\[\ce{Ar - N^+2X- ->[HBr][Cu powder] Ar - Br + N2}\]

Hoffmann Bromamide degradation reaction

Gabriel Phthalimide synthesis

Carbyl amine reaction

Gatterman reaction

Visha took 4 test-tubes namely A, B, C & D containing \[\ce{CH3CH = CH2}\], \[\ce{CH3CH2CH = CH2}\], \[\ce{CH3CH = CH - CH3}\] and \[\ce{(CH3)2C = CH2}\] respectively and tried to convert them into tertbutylalcohol. She carried out acid catalysed hydration reaction on every alkene. Out of the four test-tubes, the one which will give desired result is:

A

B

C

D

Van’t Hoff factor for \[\ce{KCl}\] solution assuming the complete dissociation is ______.

1

2

0.5

1.5

Dilution affects both conductivity as well as molar conductivity. Effect of dilution on both is as follows:

both increase with dilution.

both decrease with dilution.

conductivity increases whereas molar conductivity decreases on dilution.

conductivity decreases whereas molar conductivity increases on dilution.

Which of the following cell is used in inverter?

Fuel cell

Mercury cell

Lead storage cell

Dry cell

In which of the following molecules, C atom marked with asterisk is chiral?

I, II, III

II, III, IV

I, II, III, IV

I, III, IV

For the reaction \[\ce{A + 2B -> C + D}\]. The order of the reaction is:

1 with respect to A.

2 with respect to B.

Can’t be predicted as order is determined experimentally.

3

Assertion (A): p-methoxyphenol is a stronger acid than p-nitrophenol.

Reason (R): Methoxy group shows +I effect whereas nitro group shows −I effect.

Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).

Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).

Assertion (A) is true, but Reason (R) is false.

Assertion (A) is false, but Reason (R) is true.

Assertion (A): Inversion of configuration is observed in S_N2 reaction.

Reason (R): The reaction proceeds with the formation of carbocation.

Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).

Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).

Assertion (A) is true, but Reason (R) is false.

Assertion (A) is false, but Reason (R) is true.

Assertion (A): The units of rate constant of a zero order reaction and rate of reaction are the same.

Reason (R): In zero order reaction, the rate of reaction is independent of the concentration of reactants.

Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).

Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).

Assertion (A) is true, but Reason (R) is false.

Assertion (A) is false, but Reason (R) is true.

Assertion (A): \[\ce{Zr}\] and \[\ce{Hf}\] are of almost similar atomic radii.

Reason (R): This is due to Lanthanoid contraction.

Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).

Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).

Assertion (A) is true, but Reason (R) is false.

Assertion (A) is false, but Reason (R) is true.

Define the following term:

Faraday’s second law of electrolysis

Define corrosion.

Resistance of a conductivity cell filled with 0.2 mol L⁻¹ \[\ce{KCl}\] solution is 200 Ω. If the resistance of the same cell when filled with 0.05 mol L⁻¹ \[\ce{KCl}\] solution is 620 Ω, calculate the conductivity and molar conductivity of 0.05 mol L⁻¹ \[\ce{KCl}\] solution. The conductivity of 0.2 mol L⁻¹ \[\ce{KCl}\] solution is 0.0248 S cm⁻¹.

Show that in case of a first order reaction, the time taken for completion of 99% reaction is twice the time required for 90% completion of the reaction. (log 10 = 1)

Carry out the following conversion:

Nitrobenzene to Aniline

How do you convert the following:

Aniline to phenol

Write a chemical test to distinguish between Dimethyl amine and Ethanamine.

Write the product formed when benzene diazonium chloride is treated with KI.

Classify the following sugars into monosaccharides and disaccharides:

Fructose, Lactose, Glucose, Maltose

Give the structure of the major product expected from the following reaction:

Reaction of Ethanal with methyl-magnesium bromide followed by hydrolysis.

Give the structure of the major product expected from the following reaction:

Hydration of But-1-ene in the presence of dilute sulphuric acid.

Give the structure of the major product expected from the following reaction:

Reaction of phenol with bromine water.

A compound 'X’ with molecular formula \[\ce{C3H9N}\] reacts with \[\ce{C6H5SO2Cl}\] to give a solid, insoluble in alkali. Identify 'X’ and give the IUPAC name of the product. Write the reaction involved.

The rate constant of a reaction quadruples when the temperature changes from 300 K to 320 K. Calculate the activation energy for this reaction.

[log 2 = 0.30, log 4 = 0.60, 2.303 R = 19.15 JK⁻¹mol⁻¹]

Write IUPAC name of the following coordination compound:

\[\ce{K3[Fe(CN)6]}\]

Write IUPAC name of the following coordination compound:

\[\ce{[Pt(en)2Cl2]^2+}\]

Write IUPAC name of the following coordination compound:

\[\ce{[Co(NH3)4Cl(ONO)]Cl}\]

Write IUPAC name of the following coordination compound:

\[\ce{[Zn(OH)4]^2-}\]

Draw the structure of major product in the following reaction:

Draw the structure of major product in the following reaction:

\[\begin{array}{cc}
\ce{CH3}\phantom{.......}\ce{CH3}\phantom{......}\\
\backslash\phantom{......}/\phantom{.......}\\
\phantom{.....}\ce{C = C \phantom{.....}->[NaOI]}\\
/\phantom{......}\backslash\phantom{.......}\\
\ce{H}\phantom{........}\ce{C - CH3}\\
\phantom{...}||\\
\phantom{...}\ce{O}\\
\end{array}\]

Draw the structure of major product in the following reaction:

Calculate the emf of the following cell:

\[\ce{Ni_{(s)} + 2Ag+(0.01 M) -> Ni^{2+} (0.1 M) + 2Ag_{(s)}}\]

Given that `E_(cell)^0` = 1.05 V, log 10 = 1

Account for the following:

Haloalkanes react with \[\ce{NaCN}\] to form both cyanides and isocyanides.

Account for the following:

Haloarenes are extremely less reactive towards nucleophilic substitution reactions.

Account for the following:

Benzyl chloride gives S_N1 reaction.

The following question is a case-based question. Read the case carefully and answer the questions that follow: 

Answer the following questions:

(a) What is the other name of vitamin B₆?   (1)

(b) Name the vitamin whose deficiency causes increased blood clotting time.  (1)

(c) Xerophthalmia is caused by the deficiency of which vitamin? Give two sources of this vitamin.  (2)

                                       OR

(c) Why can’t vitamin C be stored in our body? Name the disease caused by the deficiency of this vitamin.  (2)

The following question is a case-based question. Read the case carefully and answer the questions that follow: 

Based on the above information, answer the following questions:

(a) Define ambidentate ligand with an example.  (1)

(b) What type of isomerism is shown by \[\ce{[CO(NH3)5Cl]SO4}\] and \[\ce{[Co(NH3)5SO4]Cl}\]?  (1)

(c) Define Chelate effect. How it affects the stability of complex?  (2)

                                              OR

(c) Find the coordination number and oxidation state of chromium in \[\ce{Na3[Cr(C2O4)3]}\].  (2)

An organic compound (A) with the molecular formula \[\ce{C9H10O}\] forms a 2, 4-DNP derivative, reduces Fehling solution and undergoes the Cannizzaro reaction. On vigorous oxidation, it gives 1, 2-benzene dicarboxylic acid.

1. Identify the compound (A) and write its IUPAC name.  (2)
2. Write the reaction of compound (A) with
   1. 2, 4-Dinitrophenyl hydrazine and   
   2. Fehling solution.  (2)
3. Write the equation of compound (A) when it undergoes the Cannizzaro reaction.  (1)

Why is the α-hydrogens of aldehydes and ketones are acidic in nature?

Account for the following:

Oxidation of aldehydes is easier than ketones.

Arrange the following in decreasing reactivity towards nucleophilic addition reactions:

Propanal, Acetone, Benzaldehyde

Arrange the following in increasing order of boiling point:

Propane, Ethanol, Dimethylether, Propanal

Give simple chemical tests to distinguish between the following pair of compounds:

Benzaldehyde and Benzoic acid

\[\ce{Ce(III)}\] is easily oxidised to \[\ce{Ce(IV)}\]. Comment.

E°(Mn²⁺/Mn) is −1.18 V. Why is this value highly negative in comparison to neighbouring d block elements?

Which element of 3d series has lowest enthalpy of atomisation and why?

What happens when sodium chromate is acidified?

Give reasons for the following statement:

\[\ce{Zn}\], \[\ce{Cd}\] and \[\ce{Hg}\] are soft metals.

Why \[\ce{HCl}\] should not be used for potassium permanganate titrations?

The lower oxides of transition metals are basic, whereas the highest are amphoteric/acidic. Give reason.

Ishan’s automobile radiator is filled with 1.0 kg of water. How many grams of ethylene glycol (Molar mass = 62 g mol⁻¹) must Ishan add to get the freezing point of the solution lowered to −2.8°C. K_f for water is 1.86 K kg mol⁻¹.

What type of deviation is shown by a mixture of ethanol and acetone? Give reason.

Boiling point of water at 750 mm \[\ce{Hg}\] pressure is 99.68°C. How much sucrose (Molar mass = 342 g mol⁻¹) is to be added to 500 g of water such that it boils at 100°C? (K_b for water = 0.52 K kg mol⁻¹).

State Henry's law.

Write any one application of Henry's law.