CBSE Sample Papers for Class 12 Chemistry Term 2 Set 10 for Practice

Students can access the CBSE Sample Papers for Class 12 Chemistry with Solutions and marking scheme Term 2 Set 10 will help students in understanding the difficulty level of the exam.

CBSE Sample Papers for Class 12 Chemistry Term 2 Set 10 for Practice

Time Allowed: 2 Hours
Maximum Marks: 35

General Instructions:

• There are 12 questions in this question paper with internal choice.
• SECTION A – Q. No. 1 to 3 are very short answer questions carrying 2 marks each.
• SECTION B – Q. No. 4 to 11 are short answer questions carrying 3 marks each.
• SECTION C- Q. No. 12 is case based question carrying 5 marks.
• All questions are compulsory.
• Use of log tables and calculators is not allowed.

Section – A
(Section A-Question No 1 to 3 are very short answer questions carrying 2 marks each.)

Question 1.
Calculate ∧⁰_m for acetic acid –
Given that ∧° (HCl) = 426 S cm² mol^-1
∧° (NaCl) = 126 S cm² mol^-1
∧° (CH3COONa) = 91 S cm² mol^-1 (2)

Question 2.
Define the following terms – (Any two)
(A) Order of a reaction
(B) Rate law
(C) Elementary reaction (2)

Question 3.
What products will be formed on reaction of propanal with 2-methyl propanal in the presence of NaOH? Write the name of the reaction also. (2)

Section – B
(Section B-Question No 4 to 11 are short answer questions carrying 3 marks each.)

Question 4.
Complete the following reaction sequence:

OR
Compound ‘A’ was prepared by oxidation of compound ‘B’ with alkaline KMnO₄. Compound ‘A’ on reduction with lithium aluminium hydride gets converted back to compound ‘B’. When compound ‘A’ is heated with compound ‘B’ in the presence of H₂S0₄ it produces fruity smell of compound ‘C to which family the compounds ‘A’, ‘B’ and ‘C’ belong to? (3)
(A) Redraw the diagram to show the direction of flow of current.
(B) Write the reactions taking place at anode and cathode.
(C) Construct the Nernst equation for the given Electro chemical cell. (3)

Question 5.
Observe the diagram given below and answer the questions that follow:

(A) Redraw the diagram to show the direction of flow of current.
(B) Write the reactions taking place at anode and cathode.
(C) Construct the Nernst equation for the given Electrochemical cell. (3)

Question 6.
For the reaction: 2A + B → A₂B the rate = klA] [B]² with k = 2.0 x 10^-6 mol L^-1 s. Calculate the initial rate of the reaction when [A] = 0.1 mol L^-1, [B] = 0.2 mol L^-1. CalcuLate the rate of reaction after [A] is reduced to 0.06 mol L^-1.
OR
The decomposition of NH₃ on platinum surface is zero order. What are the rates of production of N₂ and H₂ If k = 2.5 × 10³ mol L^-1 s^-1? (3)

Question 7.
What happens when:
(A) A colloidal solution undergoes persistent dialysis.
(B) River water meets sea water.
(c) Alum is applied on cuts during bleeding
OR
Answer the folLowing questions:
(A) Why is it important to have clean surface in surface studies?
(B) Why is chemisorption referred to as activated adsorption?
(C) What type of solutions are formed on dissolving different concentrations of soap in water? (3)

Question 8.
(A) Out of the following elements, identify the element which does not exhibit a variable oxidation state?
Chromium (Cr), Cobalt (Co), Zinc (Zn)
(B) Calculate the magnetic moment of Cu²⁺ (Z = 29 ) on the basis of “spin-only” formula.
(C) Out of Fe and Cu, which one would exhibit higher melting point? (3)

Question 9.
(A) Arrange the following complexes in the increasing order of conductivity of their solution:
[Co(NH₃)₃Cl₃], [CO(NH₃)4Cl₂]Cl,
[CO(NH₃)₆]Cl₃, [CO(NH₃)₅Cl]Cl₂
(B) On the basis of crystal field theory explain why Co (III) forms paramagnetic octahedral complex with weak field ligands whereas it forms diamagnetic octahedral complex with strong field ligands. (3)

Question 10.
Using crystal field theory, draw energy level diagram and write electronic configuration of the central metal ion of [Co(H₂0)]²⁺.
OR
Using valence bond theory, explain the following in relation to the complex [Mn(CN)₆]^3-:
(i) Type of hybridisation.
(ii) Inner or outer orbital complex.
(iii) Magnetic behaviour. (3)

Question 11.
(A) Alkenes (>C = <) and carbonyl compounds (>C = O), both contain a π bond but alkenes show electrophilic addition reactions whereas carbonyl compounds show nucleophilic addition reactions. Explain.
(B) Why is there a large difference in the boiling points of butanal and butan-1 -ol? (3)

Section – C
(Section C-Question No 12 is case-based question carrying 5 marks.)

Question 12.
Read the following passage and answer the questions that follow: (5)
Amines are classified as primary, secondary and tertiary amines. Primary amines cannot be obtained by ammonolysis of alkyl halide because we will get mixture of 1° 2° and 3° amines. Cyanides, on reduction give primary amines where as isocyanides on reduction give seconday amines. Nitro compounds, on reduction also give primary, amines. Primary amines react with CHCl₃ and KOH to form foul smelling isocyanide. They react with HNO₂ and liberate N₂ gas. They react with Hinsberg’s reagent to form salt soluble in KOH.

Secondary amine form yellow oily compounds with HN0₂ and salt formed with C₆H₅SO₂Cl is insoluble in KOH. 3° amines form salt soluble in water with HNO₂ but does not react with C₆H₅SO₂Cl.
(A) Name two reducing agents which can be used to prepare primary amines from nitro compounds.
(B) Write the isomer of C₃H₉N which does not react with Hinsberg’s reagent.
(C) Primary amines cannot be prepared by ammonolysis of alkyl halides. Give reason.
(D) Write structures along with the IUPAC names:
(i) the amide which gives propanamine by Hoffmann bromamide reaction.
(ii) the amine produced by the Hoffmann degradation of benzamide.
OR
(i) What is the product when C₆H₅CH₂NH₂ reacts with HNO₂?
(ii) Why does ethanol have higher boiling point than ethanamine?