CBSE Class 12 Chemistry 2022

Marks by chapter

Counted from the 99 questions listed below, as the 2022 papers print them. CBSE allocates marks per unit, not per chapter — this is what was observed, not an official CBSE weightage. Every year compared →

99 questions from 2022

• Q1Answer the following questions (Do any two): Identify the order of reaction from the following unit for its rate…2 mk
• Q1Arrange the following compounds in the increasing order of their property indicated: (Any two) (i) Acetaldehyde,…2 mk
• Q1Arrange the following compounds in increasing order of their property as indicated in bracket: (Any two ) (i)…2 mk
• Q1How will you carry out the following conversions: (Any two) (i) Propanal to Propane (ii) Ethanal to But-2-enal (iii)…2 mk
• Q1Define rate of reaction. Write two factors that affect the rate of reaction.2 mk
• Q1Predict the products formed when CH_3 CH_2 CHO reacts with the following reagents: (Any two) (i) PhMgBr and then H_3…2 mk
• Q1Predict the reagent for carrying out the following transformations: (Any two) (i) Benzoyl chloride to Benzaldehyde (ii)…2 mk
• Q1Predict the products formed when CH_3 CHO reacts with the following reagents: (Any two) (i) CH_3 MgBr and then H_3 O^+…2 mk
• Q1A reaction is second order in X and first order in Y. How is the rate affected when the concentrations of both X and Y…2 mk
• Q2In the given reaction N_2( g)+3 H_2( g) → 2 NH_3( g) the rate of formation of NH_3 is 3 · 6 × 10^-4 mol L^-1 s^-1.…2 mk
• Q2(i) Why on dilution the Λ_m of CH_3 COOH increases very fast, while that of CH_3 COONa increases gradually? (ii) What…2 mk
• Q2The resistance and conductivity of a conductivity cell containing 0.001 M KCl solution at 298 K are 1200 Ω and 1.5 ×…2 mk
• Q2In a plot of Λ_m against the square root of concentration (C^1 / 2) for strong and weak electrolyte, the value of…2 mk
• Q2In the plot of molar conductivity (Λ_m) Vs. square root of concentration (√C), following curves are obtained for two…2 mk
• Q2Arrange the following in the increasing order of the property mentioned: CH_3 COOH, ClCH_2 COOH, FCH_2 COOH (Acid…2 mk
• Q2Arrange the following in the increasing order of their property indicated: Ethanal, Propanone, Propanal, Butanone…2 mk
• Q2Explain the following reactions: Clemmensen reduction Stephen reaction2 mk
• Q2Define molar conductivity for the solution of an electrolyte. How does it vary with concentration?2 mk
• Q2Arrange the following compounds as directed: (any Two) (i) In decreasing order of basic strength in aqueous solution:…2 mk
• Q2Write the products formed when benzaldehyde reacts with the following reagents (Any two): (i) CH_3 CHO in presence of…2 mk
• Q2Observe the given figure and answer the following questions: (Any two) (i) What is the charge on AgI colloidal…2 mk
• Q2Out of the following pairs, predict with reason which will allow greater conduction of electricity: (i) 1 M CH_3 COOH…2 mk
• Q3Give reasons for the following statements: (Any two) (i) Benzaldehyde is less reactive than propanal in nucleophilic…2 mk
• Q3In a reaction 2 N_2 O_5( g) → 4 NO_2( g)+O_2( g), the concentration of N_2 O_5 decreases from 0.5 mol L^-1 to 0.4 mol…2 mk
• Q3Define conductivity for the solution of an electrolyte. Why does the conductivity of a solution decrease with dilution?2 mk
• Q3Write the Nernst equation for the following cell reaction: Zn( s)+Cu^2+(aq) → Zn^2+(aq)+Cu( s) How will the E_cell be…2 mk
• Q3The conductivity of 0.001M acetic acid is 7.8 × 10^-5 S cm^-1. Calculate its degree of dissociation if Λ^° m for acetic…2 mk
• Q3(i) State Kohlrausch's law of independent migration of ions. (ii) Calculate the degree of dissociation ( α ) of CH_3…2 mk
• Q3What do you mean by complex reactions? Can we determine order and molecularity of a complex reaction?2 mk
• Q3Write reasons for the following statements: (i) Benzoic acid does not undergo Friedel-Crafts reaction. (ii) Oxidation…2 mk
• Q3A reaction is first order in X and second order in Y. (i) How is the rate affected on increasing the concentration of Y…2 mk
• Q3Explain the following reactions: Wolff Kishner reduction Cannizzaro reaction2 mk
• Q3An Organic compound with molecular formula C_3 H_7 NO on heating with Br_2 and KOH forms a compound. Compound on…2 mk
• Q3(i) (CH_3)_3 C-CHO does not undergo aldol condensation. Why? (ii) Distinguish between Acetophenone and Benzophenone…2 mk
• Q4Account for the following: (i) pk_b of aniline is more than that of methylamine. (ii) Aniline does not undergo…3 mk
• Q4Account for the following: (i) Cr^2+ is a strong reducing agent. (ii) Ti^3+ is coloured whereas Sc^3+ is colourless in…3 mk
• Q4Write reasons for the following: (i) Ethylamine is soluble in water whereas aniline is insoluble. (ii) Amino group is o…3 mk
• Q4Write the hybridisation and magnetic character of the following complexes: (i) [NiCl_4]^2- (ii) [Co(NH_3)_6]^3+ (iii)…3 mk
• Q4Account for the following: (i) Cu^2+ salts are coloured while Zn^2+ salts are white. (ii) E^° value for the Mn^3+ /…3 mk
• Q4Predict the products in the following reactions: (i) CH_3MgBr + CO_2 →H_3O^+ (ii) CH_3CN →[(b) H_2O](a) DIBAL-H OR…3 mk
• Q4(i) Why are melting points of transition metals high? (ii) Why the transition metals generally form coloured compounds?…3 mk
• Q4Following ions of 3d-transition series are given: Ti^4+, V^3+, Cr^3+, Mn^3+ (Atomic number: Ti=22, V=23, Cr=24, Mn=25 )…3 mk
• Q5From the given E^ values of the first row transition elements, answer the following questions: (i) Why is E_Mn^2+ / Mn^…3 mk
• Q5(i) Write the IUPAC name of the following complex: [Pt(NH_3)_6] Cl_4 (ii) On the basis of crystal field theory, write…3 mk
• Q5Write the IUPAC name of the following complex: K_3[Cr(C_2 O_4)_3] On the basis of crystal field theory, write the…3 mk
• Q5Calculate Δ_r G^° and log Kc for the following cell: Ni( s)+2 Ag^+(aq) → Ni^2+(aq)+2 Ag( s); Given that E^° cell =1.05…3 mk
• Q5(i) On the basis of crystal field theory, write the electronic configuration for d^4 ion if Δ_0<P. (ii) Using valence…3 mk
• Q5(i) Write the electronic configuration of d^4 on the basis of crystal field splitting theory if Δ_0>P. (ii)…3 mk
• Q5(i) Write the electronic configuration of d^4 on the basis of crystal field splitting theory, if Δ_0<P. (ii)…3 mk
• Q5Calculate the emf of the following cell: Zn( s)|Zn^2+(0 · 01 M) ∥(0 · 001 M) Ag^+| Ag( s) Given: E_Zn^2+ / Zn^ =-0.76 V…3 mk
• Q5(i) Write the electronic configuration of d^5 on the basis of crystal field splitting theory if Δ_0<P. (ii)…3 mk
• Q5(i) Write the IUPAC name of the following complex: K_2[PdCl_4] (ii) Using crystal field theory, write the electronic…3 mk
• Q6(i) Define coagulation. (ii) State Hardy-Schulze rule. (iii) What is Electrophoresis? OR Write three differences…3 mk
• Q6Write the major products in the following: OR (i) Oxidation of propanal is easier than propanone. Why? (ii) How can you…3 mk
• Q6A first order reaction is 50% complete in 40 minutes. Calculate the time required for the completion of 90% of…3 mk
• Q6(i) Which ion amongst the following is colourless and why? Ti^4+, Cr^3+, V^3+ (Atomic number of Ti=22, Cr=24, V=23 )…3 mk
• Q7Observe the graph shown in figure and answer the following questions: What is the order of the reaction? What is the…3 mk
• Q7What is Lanthanoid contraction? What is the cause of Lanthanoid contraction? Write two consequences of Lanthanoid…3 mk
• Q7Illustrate the following reactions giving suitable example in each case: (i) Gabriel phthalimide synthesis. (ii)…3 mk
• Q7Write any two consequences of Lanthanoid Contraction. Name the element of 3d series which exhibits the largest number…3 mk
• Q7A first order reduction takes 30 minutes for 75% decomposition. Calculate t_1 / 2. Given: [ log 2=0 · 3, log 3=0 · 48,…3 mk
• Q7Differentiate between the following: (i) Adsorption and Absorption (ii) Lyophobic Sol and Lyophilic Sol (iii)…3 mk
• Q7Write the equations involved in the following reactions: (i) Cannizzaro reaction (ii) Aldol condensation (iii)…3 mk
• Q8Give reasons for the following statements: Copper does not displace hydrogen from acids. Transition metals and most of…3 mk
• Q8Observe the given figure and answer the following questions: (i) Write the expression for adsorption of gases on solids…3 mk
• Q8Give reasons for the following statements: Scandium (Z=21) is a transition element but Zn(Z=30) is not. [Ti(H_2 O)]^3+…3 mk
• Q8Give reasons for the following statements: Transition elements and their compounds act as good catalysts. E^o(Mn^2+ /…3 mk
• Q8Account for the following: (i) Zr and Hf have almost similar atomic radii. (ii) Transition metals show variable…3 mk
• Q8Following ions of 3d transition series are given: V^3+, Cr^2+, Cu^+, Fe^2+, (Atomic number: V=23, Cr=24, Cu=29, Fe=26 )…3 mk
• Q8Account for the following: (i) Transition elements have higher enthalpies of atomisation. (ii) Separation of a mixture…3 mk
• Q8A compound 'A' (C_2 H_4 O) on oxidation gives 'B' (C_2 H_4 O_2). 'A' undergoes Iodoform reaction to give yellow…3 mk
• Q8Define transition metals. Why Zn, Cd and Hg are not called transition metals? How is the variability in oxidation…3 mk
• Q8Write three differences between Lyophobic sol and Lyophilic sol. OR (i) Write the dispersed phase and dispersion medium…3 mk
• Q9Write equations involved in the following reactions: (i) Ethanamine reacts with acetyl chloride. (ii) Aniline reacts…3 mk
• Q9An organic compound 'X' with the molecular formula C_5 H_10 O forms 2,4-DNP derivative, does not reduce Tollens'…3 mk
• Q9The standard Gibbs energy (Δ r G^°) for the following cell reaction is -300 kJ mol^-1: Zn( s)+2 Ag^+(aq) → Zn^2+(aq)+2…3 mk
• Q9What happens when (i) Propanone is treated with CH_3 MgBr and then hydrolysed? (ii) Ethanal is treated with excess…3 mk
• Q10Write the equation involved in the following reactions: (i) Rosenmund reduction (ii) Etard reaction (iii) Stephen…3 mk
• Q10A compound 'A' on reduction with iron scrap and hydrochloric acid gives compound 'B' with molecular formula C_6 H_7 N.…3 mk
• Q10An aromatic compound 'A' (C_7 H_6 O_2) on reaction with aqueous ammonia and heating forms compound ' B '. ' B ' on…3 mk
• Q10Write the Nernst equation and calculate the emf of the following cell at 298 K: Zn|Zn^2+(0 · 1 M) ∥ Cd^2+(0 · 01)| Cd…3 mk
• Q10Give reasons: (i) Ammonolysis of alkyl halides is not a good method to prepare pure primary amines. (ii) Aniline does…3 mk
• Q10Write the Nernst equation and calculate the emf of the following cell at 298 K: 3 Zn|Zn^2+(0 · 001 M) ∥ H^+(0 · 01 M)|…3 mk
• Q10Write any three differences between physisorption and chemisorption. OR Define the following terms with a suitable…3 mk
• Q10Using valence bond theory, predict the hybridization and magnetic character of the complex: [Ni(CO)_4] (Atomic number:…3 mk
• Q10A primary amine 'A' C_2 H_7 N reacts with alkyl halide (C_2 H_5 I) to give secondary amine 'B'. 'B' reacts with C_6 H_5…3 mk
• Q10Write the Nernst equation and calculate emf of the following cell at 298 K: Cr|Cr^3+(0 · 1 M) ∥ Fe^2+(0 · 01 M)| Fe…3 mk
• Q10Using valence bond theory, predict the hybridization and magnetic character of following: [CoF_6]^3-[ Atomic number of…3 mk
• Q10Following ions of 3d transition series are given: Ti^2+, Fe^2+, Cu^2+, Zn^2+ (Atomic number: Ti=22, Fe=26, Cu=29, Zn=30…3 mk
• Q11(i) Silver atom has completely filled d-orbitals in its ground state, it is still considered to be a transition…3 mk
• Q11Account for the following: (i) Transition metals and their compounds show catalytic activities. (ii) Zn, Cd and Hg are…3 mk
• Q11Complete the following: (i) CH_3 CN →[ 2. H_2 O] 1. A 1 H(i-Bu)_2^′ A^′ →[H^+]H_2 N-OH 'B' (ii) Write IUPAC name of the…3 mk
• Q11(i) Which acid of the following pair would you expect to be stronger? F-CH_2-COOH or CH_3-COOH (ii) Arrange the…3 mk
• Q11Account for the following: (i) Transition metals and their compounds act as good catalysts. (ii) Eu^2+ is a strong…3 mk
• Q12Read the passage given below and answer the questions that follow: The rate law for a chemical reaction relates the…5 mk
• Q12Read the passage given below and answer the questions that follow: Oxidation-reduction reactions are commonly known as…5 mk
• Q12Read the passage given below and answer the questions that follow: Aldehydes, ketones and carboxylic acids are some of…5 mk
• Q12Read the following passage and answer the questions that follow: Amines constitute an important class of organic…5 mk
• Q12Read the following passage and answer the questions that follow: The rate of reaction is concerned with decrease in…5 mk