CBSE Class 12 Chemistry Compartment Set 2 - (56/7/2) Question Paper 2026 PDF

The quantity of electricity in Faraday, required to reduce 1 mol of \( \mathrm{Cr_2O_7^{2-}} \) to \( \mathrm{Cr^{3+}} \) is :

• (A) 4F
• (B) 3F
• (C) 6F
• (D) 5F

The relationship between \( E^{o}_{(cell)} \) and \( \Delta_rG^{\ominus} \) is :

• (A) \( \Delta_rG^{\ominus} = E^{\ominus}_{(cell)} \)
• (B) \( \Delta_rG^{\ominus} = nF\,E^{\ominus}_{(cell)} \)
• (C) \( \Delta_rG^{\ominus} = nE^{o}_{cell} \)
• (D) \( \Delta_rG^{\ominus} = -\,nF\,E^{\ominus}_{(cell)} \)

Which of the following elements exhibits maximum number of oxidation states ?

• (A) Scandium
• (B) Zinc
• (C) Manganese
• (D) Cobalt

Which of the following reactions is used for the preparation of Aniline ?

• (A) Reaction of ethanolic \( \mathrm{NH_3} \) with \( \mathrm{C_6H_5Cl} \)
• (B) Reaction of Nitrobenzene with Hydrogen gas in presence of finely divided Nickel
• (C) Reaction of Benzamide with \( \mathrm{LiAlH_4} \)
• (D) Reaction of Benzonitrile with \( \mathrm{LiAlH_4} \)

The products of the following reaction are :

\( \mathrm{C_6H_5CH_2OC_6H_5} \xrightarrow{\mathrm{HI}} \)

(i) \( \mathrm{C_6H_5CH_2I} \)

(ii) \( \mathrm{C_6H_5OH} \)

(iii) \( \mathrm{C_6H_5OCH_3} \)

• (A) (i) and (ii)
• (B) (i) and (iii)
• (C) (ii) and (iii)
• (D) (i), (ii) and (iii)

Which of the following statements is true about a galvanic cell consisting of Cu and \( \mathrm{H_2} \) electrodes ?

[Given : \( E^{o}_{\mathrm{Cu^{2+}/Cu}} = +0.34\ \mathrm{V},\ E^{o}_{\mathrm{H^{+}/H_2,\ Pt}} = 0.00\ \mathrm{V} \)]

• (A) Oxidation occurs at copper electrode
• (B) Reduction occurs at \( \mathrm{H_2} \) electrode
• (C) \( \mathrm{H_2} \) is cathode and Cu is anode
• (D) \( \mathrm{H_2} \) is anode and Cu is cathode

The correct order of reactivity of alcohols with Lucas reagent is :

• (A) \( 3^{\circ} > 1^{\circ} > 2^{\circ} \)
• (B) \( 2^{\circ} > 1^{\circ} > 3^{\circ} \)
• (C) \( 1^{\circ} > 2^{\circ} > 3^{\circ} \)
• (D) \( 3^{\circ} > 2^{\circ} > 1^{\circ} \)

Match Column I with Column II and choose the correct option :

• (A) a-i, b-ii, c-iii, d-iv
• (B) a-ii, b-i, c-iii, d-iv
• (C) a-iv, b-iii, c-ii, d-i
• (D) a-ii, b-iv, c-i, d-iii

Phenol, on heating with conc. \( \mathrm{HNO_3} \), gives :

• (A) o-Nitrophenol
• (B) p-Nitrophenol
• (C) Picric acid
• (D) Sodium phenoxide

Functional groups present in amino acids are :

• (A) \( \mathrm{-NH_2} \) and \( \mathrm{-OH} \)
• (B) \( \mathrm{-OH} \) and \( \mathrm{-COOH} \)
• (C) \( \mathrm{-COOH} \) and \( \mathrm{-NH_2} \)
• (D) \( \mathrm{-NH_2} \) and \( \mathrm{-SO_3H} \)

According to Alfred Werner, the secondary valence(s) of the central metal atom/ion in a complex :

Identify the incorrect statement from the given statements.

• (A) are non-ionisable
• (B) are ionisable
• (C) are satisfied by neutral molecules or negative ions
• (D) is equal to the coordination number and is normally fixed for a metal

A galvanic cell functions like an electrolytic cell when :

• (A) \( E_{cell} = E_{ext} \)
• (B) \( E_{cell} > E_{ext} \)
• (C) \( E_{ext} > E_{cell} \)
• (D) \( E_{cell} = 0 \)

Assertion (A) : Aromatic carboxylic acids do not undergo Friedel-Crafts reaction.

Reason (R) : Carboxyl group is deactivating and the catalyst aluminium chloride gets bonded to carboxyl group.

• (A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
• (B) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
• (C) Assertion (A) is true, but Reason (R) is false.
• (D) Assertion (A) is false, but Reason (R) is true.

Assertion (A) : The volume of an ideal solution is equal to the sum of the volumes of the two components, i.e., \( \Delta_{mix}V = 0 \).

Reason (R) : The intermolecular forces of attraction between the solute-solvent molecules are weaker than those between the solute-solute and solvent-solvent molecules.

• (A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
• (B) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
• (C) Assertion (A) is true, but Reason (R) is false.
• (D) Assertion (A) is false, but Reason (R) is true.

Assertion (A) : Out of \( \mathrm{[Co(en)_3]^{3+}} \) and \( \mathrm{[Co(CN)_6]^{3-}} \), coordination compound \( \mathrm{[Co(en)_3]^{3+}} \) is a more stable complex.

Reason (R) : Ethane-1,2-diamine is a chelating ligand.

• (A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
• (B) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
• (C) Assertion (A) is true, but Reason (R) is false.
• (D) Assertion (A) is false, but Reason (R) is true.

Assertion (A) : Phosphorus halides are preferred over thionyl chloride for the preparation of alkyl halides from alcohols.

Reason (R) : Reaction of alcohols with thionyl chloride forms pure alkyl halides.

• (A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
• (B) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
• (C) Assertion (A) is true, but Reason (R) is false.
• (D) Assertion (A) is false, but Reason (R) is true.

10 g of a non-volatile solute is dissolved in 200 g of water to make a solution. It has a vapour pressure of 31.84 mm Hg at 308 K.

Calculate the molar mass of the solute.

[Given : Vapour pressure of pure water at 308 K = 32 mm Hg]

A reaction is of first order with respect to A and of second order with respect to B. How is the rate of reaction affected, when the concentration of (i) both A and B are doubled, and (ii) A is doubled and B is reduced to half ?

Write the reactions taking place at anode and cathode in a dry cell.

(i) Why do Zr and Hf exhibit similar properties ?

(ii) "\( E^\circ \) for \( \mathrm{Mn^{3+}/Mn^{2+}} \) couple is more positive than that for \( \mathrm{Fe^{3+}/Fe^{2+}} \)." Justify the statement.

[Atomic number : Mn = 25, Fe = 26]

(i) Which element in 3d series of transition elements does not exhibit variable oxidation states ? Give reason.

(ii) Explain why \( \mathrm{Cu^{+}} \) is colourless in aqueous solution, whereas \( \mathrm{Cu^{2+}} \) is coloured.

(a) Write the IUPAC name of the given compound :

\( \mathrm{H_2C=C(CH_3)-CH(Br)-CH_2Br} \)

(b) Arrange the following compounds in decreasing order of their boiling points :

1-Chlorobutane, Isopropyl chloride, 1-Chloropropane

(i) Give a chemical test to distinguish between benzaldehyde and ethanal.

(ii) Which of the given acids is stronger and why ?

\( \mathrm{CH_2FCH_2CH_2COOH} \) or \( \mathrm{CH_2CHFCH_2COOH} \)

(iii) Complete the given equation :

\( \mathrm{C_6H_5COOC_2H_5} \; \overset{\mathrm{H_3O^+}}{\rightleftharpoons} \)

An organic compound with the molecular formula \( \mathrm{C_9H_{10}O} \) forms 2,4-DNP derivative, reduces Tollens' reagent and undergoes Cannizzaro reaction. On vigorous Oxidation, it gives phthalic acid. Identify the compound. Write the reaction of this compound with Tollens' reagent and Cannizzaro reaction.

2 g of \( \mathrm{Na_2SO_4} \) is dissolved in 50 g of water to form a solution. Calculate the freezing point of this solution, assuming \( \mathrm{Na_2SO_4} \) undergoes complete dissociation.

[Given : Molar mass of \( \mathrm{Na_2SO_4} \) = 142 g \( \mathrm{mol^{-1}} \), \( K_f \) for water = 1.86 K kg \( \mathrm{mol^{-1}} \)]

(a) Arrange the following compounds in the decreasing order of their acidic strength :

Phenol, 4-Nitrophenol, 2,4,6-Trinitrophenol

(b) Why are alcohols more soluble in water than hydrocarbons of comparable molecular masses ?

(c) Name the reagent used in the oxidation of a primary unsaturated alcohol to an aldehyde.

(a) Mention any two bases present in DNA.

(b) Which component of starch is an unbranched chain polymer of \( \alpha \)-D-(+) glucose ? Write its one characteristic feature.

(c) Write the name of the linkage present between amino acids. How is it represented ?

(a) When alkyl chlorides are treated with aqueous KOH, alcohol is formed, whereas when alkyl chlorides are treated with alcoholic KOH, alkenes are formed. Explain.

(b) Complete the given equation :

\( \mathrm{C_6H_5Cl} + \mathrm{CH_3COCl} \xrightarrow{\text{Anhyd. } \mathrm{AlCl_3}} \)

The electrical resistance of a column of 0.05 M KOH solution of area 0.5 cm\(^2\) and length 50 cm is 2.5 \(\times\) 10\(^4\) ohm. Calculate its molar conductivity.

(a) What are anomers ? Explain.

(b) What happens when glucose reacts with hydroxylamine ? Write the reaction involved.

(c) Name the disease caused by the deficiency of Vitamin B\(_{12}\).

Atomic radii is a useful property for determining many aspects of chemistry of elements such as physical and chemical properties. The periodic table greatly assists in finding a number of trends. The transition metals belong to group 3 - 12 and are generally characterised by partially filled d-orbitals in the free elements or their cations. The atomic radii of transition metals show a small decrease from left to right across a period, then remain nearly constant, and finally, slight increase towards the end of the series. The trend is a result of interplay between the increasing nuclear charge and the increasing shielding effect from the filling of d-orbitals. Initially the nuclear charge dominates, leading to decrease in size, but as more d-electrons are added, their shielding becomes more effective, balancing the increased nuclear charge and causing the radii to become constant.

The increase in size between 3d and 4d metals is much greater than between the 4d and 5d metals. The atomic radii of 2^nd and 3^rd series are almost the same due to lanthanoid contraction. Increase in density is also observed on moving from left to right in a period.

Atomic radii is a useful property for determining many aspects of chemistry of elements such as physical and chemical properties. The periodic table greatly assists in finding a number of trends. The transition metals belong to group 3 - 12 and are generally characterised by partially filled d-orbitals in the free elements or their cations. The atomic radii of transition metals show a small decrease from left to right across a period, then remain nearly constant, and finally, slight increase towards the end of the series. The trend is a result of interplay between the increasing nuclear charge and the increasing shielding effect from the filling of d-orbitals. Initially the nuclear charge dominates, leading to decrease in size, but as more d-electrons are added, their shielding becomes more effective, balancing the increased nuclear charge and causing the radii to become constant.

The increase in size between 3d and 4d metals is much greater than between the 4d and 5d metals. The atomic radii of 2^nd and 3^rd series are almost the same due to lanthanoid contraction. Increase in density is also observed on moving from left to right in a period.

Atomic radii is a useful property for determining many aspects of chemistry of elements such as physical and chemical properties. The periodic table greatly assists in finding a number of trends. The transition metals belong to group 3 - 12 and are generally characterised by partially filled d-orbitals in the free elements or their cations. The atomic radii of transition metals show a small decrease from left to right across a period, then remain nearly constant, and finally, slight increase towards the end of the series. The trend is a result of interplay between the increasing nuclear charge and the increasing shielding effect from the filling of d-orbitals. Initially the nuclear charge dominates, leading to decrease in size, but as more d-electrons are added, their shielding becomes more effective, balancing the increased nuclear charge and causing the radii to become constant.

The increase in size between 3d and 4d metals is much greater than between the 4d and 5d metals. The atomic radii of 2^nd and 3^rd series are almost the same due to lanthanoid contraction. Increase in density is also observed on moving from left to right in a period.

Atomic radii is a useful property for determining many aspects of chemistry of elements such as physical and chemical properties. The periodic table greatly assists in finding a number of trends. The transition metals belong to group 3 - 12 and are generally characterised by partially filled d-orbitals in the free elements or their cations. The atomic radii of transition metals show a small decrease from left to right across a period, then remain nearly constant, and finally, slight increase towards the end of the series. The trend is a result of interplay between the increasing nuclear charge and the increasing shielding effect from the filling of d-orbitals. Initially the nuclear charge dominates, leading to decrease in size, but as more d-electrons are added, their shielding becomes more effective, balancing the increased nuclear charge and causing the radii to become constant.

The increase in size between 3d and 4d metals is much greater than between the 4d and 5d metals. The atomic radii of 2^nd and 3^rd series are almost the same due to lanthanoid contraction. Increase in density is also observed on moving from left to right in a period.

Organic compounds containing carbonyl group as the functional group are aldehydes, ketones and carboxylic acids. The carbon-oxygen double bond is polarised due to higher electronegativity of oxygen as compared to carbon. Aldehydes are generally more reactive than ketones in nucleophilic addition reactions due to steric and electronic reasons. They react with HCN, Sodium bisulphite, Grignard reagent and a number of ammonia derivatives like Hydroxylamine, Hydrazine, Semicarbazide, etc. Aldehydes and ketones undergo various reactions due to the acidic nature of \( \alpha \)-hydrogen. Aldehydes and ketones having at least one \( \alpha \)-hydrogen atom undergo a reaction in the presence of dilute alkali as a catalyst to form \( \beta \)-hydroxy aldehydes or \( \beta \)-hydroxy ketones. On the other hand, aldehydes which do not possess an \( \alpha \)-hydrogen undergo self-oxidation and reduction in the presence of concentrated alkali.

(i) Arrange the following compounds in increasing order of reactivity towards nucleophilic addition reactions :

Butanone, Propanone, Propanal, Ethanal

(ii) Draw the structure of the semicarbazone of cyclohexanone.

Organic compounds containing carbonyl group as the functional group are aldehydes, ketones and carboxylic acids. The carbon-oxygen double bond is polarised due to higher electronegativity of oxygen as compared to carbon. Aldehydes are generally more reactive than ketones in nucleophilic addition reactions due to steric and electronic reasons. They react with HCN, Sodium bisulphite, Grignard reagent and a number of ammonia derivatives like Hydroxylamine, Hydrazine, Semicarbazide, etc. Aldehydes and ketones undergo various reactions due to the acidic nature of \( \alpha \)-hydrogen. Aldehydes and ketones having at least one \( \alpha \)-hydrogen atom undergo a reaction in the presence of dilute alkali as a catalyst to form \( \beta \)-hydroxy aldehydes or \( \beta \)-hydroxy ketones. On the other hand, aldehydes which do not possess an \( \alpha \)-hydrogen undergo self-oxidation and reduction in the presence of concentrated alkali.

(i) (I) Explain why \( \mathrm{[Fe(CN)_6]^{3-}} \) is an inner orbital complex, whereas \( \mathrm{[FeF_6]^{3-}} \) is an outer orbital complex.

[Atomic number : Fe = 26]

(II) Write the formula of the given complex :

Hexaamminenickel (II) chloride

(ii) A solution of \( \mathrm{[Ni(H_2O)_6]^{2+}} \) is green in colour while a solution of \( \mathrm{[Ni(CN)_4]^{2-}} \) is colourless. Explain.

[Atomic number : Ni = 28]

(i) (I) Write IUPAC name of the given complexes :

\( \mathrm{[Ag(CN)_2]} \) \( \mathrm{[Ag(NH_3)_2]} \)

(II) What is the coordination number of the central metal ion in the following complexes ?

\( \mathrm{[Fe(C_2O_4)_3]^{3-}} \) and \( \mathrm{[Cr(NH_3)_3Cl_3]} \)

(III) Draw a geometrical isomer of the complex \( \mathrm{[CoCl_2(en)_2]^+} \), which is optically active.

(ii) Using valence bond theory, explain the hybridization of \( \mathrm{[Ni(CO)_4]} \) and its magnetic behaviour.

[Atomic number : Ni = 28]

(i) (I) The \(\mathrm{pK_b}\) value of aniline is higher than that of methylamine. Explain why.

(II) Arrange the following compounds in decreasing order of their basic strength in the gaseous phase :

\(\mathrm{NH_3}\), \(\mathrm{(C_2H_5)_2NH}\), \(\mathrm{(C_2H_5)_3N}\), \(\mathrm{C_2H_5NH_2}\)

(III) What is Hinsberg's reagent ? Mention its one use.

(ii) How will you convert the following :

(I) Nitrobenzene to Benzenediazonium chloride ?

(II) Iodomethane to Ethanamine ?

(i) Complete the following equations :

(I) \( \mathrm{CH_3NH_2 + C_6H_5COCl} \longrightarrow \)

(II) \( \mathrm{C_6H_5NH_2} \) + 3 \( \mathrm{Br_2} \) \( \xrightarrow{\mathrm{H_2O}} \)

(III) \( \mathrm{C_6H_5CONH_2} \) \( \xrightarrow{\mathrm{NaOBr}} \)

(ii) (I) Explain the carbylamine reaction.

(II) Why can aromatic primary amines not be prepared by the Gabriel phthalimide synthesis ?

(i) For first order reaction, calculate the ratio between the time taken to complete \( \frac{3}{4} \)th of the reaction and the time taken to complete half of the reaction.

(ii) (I) What is meant by a complex reaction ?

(II) Give an example of a pseudo first order reaction.