Chemistry Delhi Set - 3 2023-2024 Science (English Medium) Class 12 Question Paper Solution

Van’t Hoff factor for \[\ce{K2SO4}\] solution, assuming complete ionization is ______.

1

3

13

2

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 species can act as the strongest base?

\[\ce{OH-}\]

\[\ce{C6H5O-}\]

\[\ce{RO-}\]

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

I, II, III

I, II, III, IV

II, III, IV

I, III, IV

The rate of a reaction increases sixteen times when the concentration of the reactant increases four times. The order of the reaction is ______.

2.5

2.0

1.5

0.5

Which of the following cell is used in hearing aids?

Mercury cell

\[\ce{H2 - O2}\] fuel cell

Dry cell

\[\ce{Ni - CD}\] cell

Isotonic solutions have the same ______.

density 

refractive index

osmotic pressure

volume

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

more hard

more soft

more ductile

more metallic

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

Tear gas

Mustard gas

Phosgene gas

Chlorine gas

Phosphine 

Out of the following alkenes, the one which will produce tertiary butyl alcohol on acid catalysed hydration is:

\[\ce{CH3CH2CH = CH2}\]

\[\ce{CH3CH = CH2}\]

\[\ce{CH3 - CH = CH - CH3}\]

\[\ce{(CH3)2C = CH2}\]

The correct name of the given reaction is:

\[\ce{Ar - N+2X- ->[Cu CN/KCN] Ar - CN + N2}\]

Sandmeyer’s reaction

Gabriel Phthalimide synthesis

Carbyl amine reaction

Hoffmann bromamide degradation reaction

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

Primary structure

Secondary structure

Tertiary structure

Quaternary structure

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.

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

Reason (R): Methoxy group exerts +R effect at both ortho and para position.

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 when 1-Bromobutane is hydrolysed.

Reason (R): The reaction is S_N2 and proceeds with the formation of transition state.

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.

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.

Define limiting molar conductivity.

Define the following term:

Fuel cell

Classify the following sugars into monosaccharides and disaccharides:

Sucrose, Lactose, Glucose, Fructose

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.

A first order reaction takes 40 min for 75% decomposition. Calculate rate constant.

[Given: log 2 = 0.30, log 4 = 0.60]

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.

Account for the following:

Haloalkanes react with \[\ce{AgCN}\] to form isocyanide as main product.

Account for the following:

Allyl chloride shows high reactivity towards S_N1 reaction.

Account for the following:

Haloarenes are extremely less reactive towards nucleophilic substitution reactions.

Write the IUPAC name of the following coordination compound.

\[\ce{[Co(NH3)4Cl(NO2)]Cl}\]

Write the IUPAC name of the following coordination compound:

\[\ce{[Ni(NH3)6]Cl2}\]

Write the IUPAC name of the following coordination compound:

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

Write the IUPAC name of the following coordination compound:

\[\ce{[Co(en)2Br2]+}\]

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

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

Reaction of propanal with methyl magnesium bromide followed by hydrolysis.

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

Reaction of phenol with \[\ce{Br2 in CS2}\].

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

Reaction of propene with diborane followed by oxidation.

The rate constant of a reaction quadruples when the temperature changes from 700 K to 720 K. Calculate the activation energy for this reaction.

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

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) What is the secondary valence of \[\ce{Co}\] in \[\ce{[Co(NH3)4Cl2]+}\]?  (1)

(b) What type of isomerism is shown by the complex \[\ce{[Cr(H2O)6]Cl3}\] and \[\ce{[Cr(H2O)5Cl]Cl2 . H2O}\]?  (1)

(c) Write the electronic configuration of d⁴ ion on the basis of crystal field theory when

1. Δ₀ < P
2. Δ₀ > P  (2)

                                            OR

(c) Find the oxidation state and coordination number of the central metal ion in \[\ce{[Co(H2O)(CN)(en)2]^2+]}\].  (2)

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)

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.

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.