CBSE Class 12 Chemistry 2025

Marks by chapter

Counted from the 335 questions listed below, as the 2025 papers print them. CBSE allocates marks per unit, not per chapter — this is what was observed, not an official CBSE weightage. Every year compared →

335 questions from 2025

• Q1With increase in atomic number, the melting point of transition metals:1 mk
• Q1In case of association, abnormal molar mass of solute will1 mk
• Q1The role of a catalyst is to change:1 mk
• Q1Which of the following transition metal ion is not coloured?1 mk
• Q1Which by-product is obtained in the manufacture of phenol from cumene?1 mk
• Q1The charge required for the reduction of 1 mol of MnO_4^- to MnO_2 is1 mk
• Q1During dehydration of alcohol to alkene by heating with conc. H_2 SO_4, the initiation step is:1 mk
• Q1Among the following outermost electronic configurations of transition metals, which one shows the highest oxidation…1 mk
• Q1Williamson synthesis of preparing unsymmetrical ether is:1 mk
• Q1In an electrochemical cell, the following reaction takes place: 2 Cu^+(aq)+Zn( s) → 2 Cu( s)+Zn^2+(aq); E_cell^°=1 · 28…1 mk
• Q2Which of the following molecules is chiral in nature?1 mk
• Q2Which of the following solution in water will have the lowest freezing point?1 mk
• Q2Out of Fe^3+, Sc^3+, Cr^3+ and Co^3+ ions, the one which is colourless in aqueous solution is:1 mk
• Q2Which of the following solutions will have the highest boiling point in water?1 mk
• Q2Which among the following is a false statement?1 mk
• Q2Which of the following aqueous solutions will have the highest osmotic pressure?1 mk
• Q2Which reagents are required for one step conversion of chlorobenzene to toluene?1 mk
• Q2Out of Ti^3+, Cr^3+, Fe^2+ and Ni^2+ ions, the one which is the most stable ion in aqueous solution is:1 mk
• Q2Which reagents are required for one step conversion of Chlorobenzene to Diphenyl?1 mk
• Q2Which of the following compounds would be hydrolysed by aqueous KOH most easily?1 mk
• Q2Standard electrode potential for Sn^4+ / Sn^2+ couple is +0.15 V and that for the Cr^3+ / Cr couple is -0.74 V. The two…1 mk
• Q3During electrolysis of dilute H_2 SO_4, using platinum electrodes, the gas evolved at the anode is:1 mk
• Q3Kohlrausch gave the following relation for strong electrolytes: Λ_m=Λ_m^°-A √C Which of the following equality holds…1 mkasked 2×
• Q3The number of molecules that react with each other in an elementary reaction is a measure of the:1 mk
• Q3A conductivity cell usually consists of two:1 mk
• Q3CH_3 CH_2 OH can be converted to CH_3 CHO by:1 mk
• Q3Coordination number of Fe in [Fe(C_2 O_4)_3]^3- is:1 mk
• Q3Hoffmann Bromamide degradation reaction is given by:1 mk
• Q3Which of the following complexes show linkage isomerism?1 mk
• Q3According to Werner's theory of coordination compounds:1 mk
• Q3The magnetic moment is associated with its spin angular momentum and orbital angular momentum. Spin only magnetic…1 mk
• Q4The element having [Ar] 3 d^10 4 s^1 electronic configuration is1 mk
• Q4Acidified KMnO_4 oxidises sulphite to1 mk
• Q4The activation energy (E_a) of a reaction can be determined from the slope of which of the following plots?1 mk
• Q4Which of the following transition metals has the highest melting point?1 mk
• Q4In the Haworth structure of the following carbohydrate, various carbon atoms have been numbered. The anomeric carbon is…1 mk
• Q4Which of the following complexes shows geometrical isomerism?1 mk
• Q4Unit of rate constant 'k' for a second order reaction is:1 mk
• Q4Which of the following is the slope of the first order reaction in the plot of ln [R] vs. time?1 mk
• Q4Which of the following complex ion is not optically active?1 mk
• Q4The IUPAC name for CH_3-CH_2-N(CH_3)-CH_2-CH_2-CH_3 is:1 mk
• Q5The value of Henry's constant K_H is:1 mk
• Q5Which of the following is the softest metal?1 mk
• Q5Which of the following does not show variable oxidation state?1 mk
• Q5The complex ions [Co(NH_3)_5(NO_2)]^2+ and [Co(NH_3)_5(ONO)]^2+ are called1 mk
• Q5The correct IUPAC name of [Pt(NH_3)_2 Cl_2]^2+ is1 mk
• Q5Which of the following represents the fraction of molecules with energies equal to or greater than E_a?1 mk
• Q6Out of the following statements, the incorrect statement is:1 mk
• Q6The diamagnetic species is:1 mk
• Q6The number of moles of AgCl precipitated when excess AgNO_3 solution is mixed with one mole of [Co(NH_3)_4 Cl_2] Cl is:1 mk
• Q6The reagent that can be used to convert benzenediazonium chloride to benzonitrile is:1 mk
• Q6Arrange the following compounds in increasing order of their boiling points: (i) (ii) CH_3CH_2CH_2CH_2Br (iii) The…1 mk
• Q6The treatment of ethyl bromide with alcoholic silver nitrite gives:1 mk
• Q6In the Hinsberg's method for separation of primary, secondary and tertiary amines, the reagent used is:1 mk
• Q6The number of moles of AgCl precipitated when excess AgNO_3 solution is mixed with one mole of [Co(NH_3)_3 Cl_3] is:1 mk
• Q6The reagent that can be used to convert benzenediazonium chloride to benzene is:1 mk
• Q6Out of the following statements, the correct statement is:1 mk
• Q6The number of moles of AgCl precipitated when excess AgNO_3 solution is mixed with one mole of [Co(NH_3)_6] Cl_3 is:1 mk
• Q7A plot between concentration of reactant [R] and time 't' is shown below. Which of the given order of reaction is…1 mk
• Q7Which of the following aqueous solutions will have the highest freezing point?1 mk
• Q7Which is the correct IUPAC name for1 mk
• Q7Which of the following haloalkanes react with aqueous KOH most rapidly by S_N 1 reaction?1 mk
• Q7Which of the following haloalkanes is most reactive towards S_N 2 reaction?1 mk
• Q7The gas evolved when methylamine reacts with HNO_2 is:1 mk
• Q7Which one of the following amines gives an alcohol on reaction with HNO_2?1 mk
• Q7Out of 2-Bromobutane, 1-Bromobutane, 2-Bromopropane and 1-Bromopropane, the molecule which is chiral in nature is:1 mk
• Q7The strongest base in aqueous solution among the following amines is:1 mk
• Q7Alkyl halides undergoing nucleophilic bimolecular substitution reaction involve1 mk
• Q7The synthesis of alkyl fluoride is best carried out by:1 mk
• Q8What will be formed after oxidation reaction of secondary alcohol with chromic anhydride (CrO_3)?1 mk
• Q8A solution of acetone in chloroform:1 mk
• Q8The reaction R-OH+Na → RO^- Na^++1/2 H_2( g) suggests that alcohols are:1 mk
• Q8Which of the following aldehydes will undergo Cannizzaro reaction?1 mk
• Q8The reaction suggests that phenol is:1 mk
• Q8Which is the correct order of acid strength from the following?1 mk
• Q8In the given reaction sequence, the structure of Y would be:1 mk
• Q8The freezing point of one molal KCl solution, assuming KCl to be completely dissociated in water, is: (K_f. for…1 mk
• Q8On mixing 30 mL of acetone with 20 mL of chloroform, the total volume of solution is:1 mk
• Q8In the reaction R-OH+HCl →ZnCl_2 RCl+H_2 O, what is the correct order of reactivity of alcohols?1 mkasked 2×
• Q9The acid formed when propyl magnesium bromide is treated with CO_2 followed by acid hydrolysis is:1 mk
• Q9Phenol reacts with conc. HNO_3 to form:1 mk
• Q9Which of the following properties of transition metals enables them to behave as catalysts?1 mk
• Q9The product of the oxidation of I^- with MnO_4^- in alkaline medium is:1 mk
• Q9A solution of acetone in ethanol:1 mk
• Q9In an electrochemical cell, the following reaction takes place: 2 Ag^+(aq)+Mg( s) → 2 Ag( s)+Mg^2+(aq); E_cell^°=2 · 96…1 mk
• Q9The conversion of phenol to salicylic acid can be accomplished by1 mk
• Q9Phenol reacts with Bromine (Br_2) water to form:1 mk
• Q9At low temperature, phenol reacts with Br_2 in CS_2 to form:1 mk
• Q9We cannot measure the resistance of an ionic solution using DC because:1 mk
• Q9In which of the following groups are both ions coloured in aqueous solution? I. Cu^+ II. Ti^4+ III. Co^2+ IV. Fe^2+…1 mk
• Q10The best reagent for converting propanamide into propanamine is.1 mk
• Q10When excess of alkyl iodide is treated with ammonia, the product obtained is:1 mk
• Q10The primary and secondary valences of Co in [Co(en)_3] Cl_3 respectively are:1 mk
• Q10When alkyl iodide is treated with large excess of ammonia, the major product obtained is:1 mk
• Q10A galvanic cell can behave like an electrolytic cell when1 mk
• Q10Which is the correct IUPAC name for1 mk
• Q10Which of the following cell converts the energy of combustion of fuel into electrical energy?1 mk
• Q10CH_3 CH_2 CHO and CH_3 CH_2 COOH can be distinguished by:1 mk
• Q10Anilinium hydrogen sulphate on heating at 453-473 K produces which of the following as a major product?1 mk
• Q10Polyhalogen compounds have wide application in industries and agriculture. DDT is also a very important polyhalogen…1 mk
• Q10What amount of electric charge is required for the oxidation of 1 mole of FeO to Fe_2 O_3?1 mk
• Q10Which of the following is/are examples of denaturation of protein?1 mk
• Q10Out of Ti^3+, Cr^3+, Mn^2+ and Ni^2+ ions, the one which has the highest magnetic moment is:1 mk
• Q11What amount of electric charge is required for the reduction of 1 mole of MnO_4^- into Mn^2+?1 mk
• Q11In the Arrhenius equation k=Ae^-E_a / RT, 'A' represents:1 mk
• Q11Which of the following amines does not give foul smell of isocyanide on heating with chloroform and ethanolic KOH?1 mk
• Q11An amine 'X' reacts with Hinsberg reagent and the product obtained is soluble in alkali. The amine 'X' is:1 mk
• Q11Which of the following statements is not true about glucose?1 mk
• Q11Nucleotides are joined together by1 mk
• Q11The value of rate constant for a pseudo first order reaction:1 mk
• Q11Match the type of cell given in Column I with their use given in Column II.1 mk
• Q11An amine 'X' reacts with Hinsberg reagent and the product obtained is insoluble in alkali. The amine 'X' is:1 mk
• Q11The unit of rate and rate constant are same for a:1 mk
• Q12What amount of electric charge is required for the oxidation of 1 mole of H_2 O to O_2?1 mk
• Q12Pyranose ring of glucose is formed due to the reaction between:1 mk
• Q12Furanose ring of fructose is formed due to reaction between:1 mk
• Q12An unripe mango placed in a concentrated salt solution to prepare pickle, shrivels because.1 mk
• Q12Deficiency of vitamin B_1 causes the disease:1 mk
• Q12'Scurvy' is caused due to the deficiency of:1 mk
• Q12While doing qualitative analysis in chemistry lab, Abhishek added yellow coloured potassium chromate solution into a…1 mk
• Q12Scurvy is caused due to deficiency of1 mk
• Q12α -D-glucose and β -D-glucose differ from each other with respect to the:1 mk
• Q12α -helix structure refers to:1 mk
• Q12Alkenes are formed by heating alcohols with conc. H_2 SO_4. The first step in the reaction is:1 mk
• Q13Assertion: Cuprous salts are diamagnetic. Reason (R): In cuprous ion, 3d-orbitals are partially filled.1 mk
• Q13Assertion: A mixture of o -nitrophenol and p -nitrophenol can be separated by steam distillation. Reason(R): o…1 mk
• Q13Assertion: A mixture of o -nitrophenol and p -nitrophenol can be separated by steam distillation. Reason(R): o…1 mk
• Q13Assertion: For measuring resistance of an ionic solution an AC source is used. Reason (R): Concentration of ionic…1 mk
• Q13Assertion: Actinoids show wide range of oxidation states. Reason (R): Actinoids are radioactive in nature.1 mkasked 2×
• Q13Assertion: In a first order reaction, if the concentration of the reactant is doubled, its half-life is also doubled.…1 mk
• Q13Assertion: Electrolysis of aqueous NaCl gives H_2 at cathode and Cl_2 at anode. Reason (R): Chlorine has higher…1 mk
• Q13Assertion: A mixture of o -nitrophenol and p -nitrophenol can be separated by fractional distillation. Reason(R): o…1 mk
• Q13Assertion: Actinoid contraction is greater from element to element than lanthanoid contraction. Reason (R): Actinoids…1 mk
• Q13Assertion: [Cr(H_2 O)_6] C l_2 and [Fe(H_2 O)_6] C l_2 are examples of homoleptic complexes. Reason (R): All the…1 mk
• Q13Assertion: Actinoids show wide range of oxidation states. Reason (R): This is due to comparable energies of 5f, 6d and…1 mk
• Q14Assertion: Hydrolysis of an ester follows first order kinetics. Reason (R): The concentration of water does not get…1 mk
• Q14Assertion: The boiling points of alkyl halides decrease in the order: RI>RBr>RCl>RF. Reason (R): The boiling points of…1 mk
• Q14Assertion: Cooking time is reduced in pressure cooker. Reason (R): Boiling point of water inside the pressure cooker is…1 mk
• Q14Assertion: Cooking time is reduced in pressure cooker. Reason (R): Boiling point of water inside the pressure cooker is…1 mk
• Q14Assertion: Order of the reaction can be zero or fractional. Reason (R): We cannot determine order from balanced…1 mk
• Q14Assertion: Acetanilide is more basic than aniline. Reason (R): Acetylation of aniline results in decrease of electron…1 mk
• Q14Assertion (A): Cuprous salts are diamagnetic. Reason (R): Cuprous ion has completely filled 3d-orbitals.1 mk
• Q14Assertion (A): Aquatic species are more comfortable in cold water than in warm water. Reason (R): Solubility of oxygen…1 mk
• Q14Assertion: Henry's law constant (K_H) decreases with increase in temperature. Reason (R): As the temperature increases,…1 mk
• Q14Assertion: Cu cannot liberate H_2 on reaction with dilute mineral acids. Reason (R): Cu has positive electrode…1 mk
• Q14Assertion: Molecularity of reaction is determined experimentally. Reason (R): Molecularity is applicable only for an…1 mk
• Q15Assertion: Actinoids show irregularities in their electronic configurations. Reason (R): This is due to varying…1 mk
• Q15Assertion (A): n-Butyl chloride has higher boiling point than n-Butyl bromide. Reason (R): C - Cl bond is more polar…1 mk
• Q15Assertion: The boiling point of ethanol is higher than that of methoxymethane. Reason (R): There is intramolecular…1 mk
• Q15Assertion: Actinoids show irregularities in their electronic configurations. Reason (R): Actinoids are radioactive in…1 mk
• Q15Assertion: Boiling point of (CH_3)_3 N is higher than that of CH_3 CH_2 CH_2 NH_2. Reason (R): Hydrogen bonding is more…1 mk
• Q15Assertion: Boiling point of (C_2 H_5)_2 NH is lower than that of n-C_4 H_9 NH_2. Reason (R): Hydrogen bonding is much…1 mk
• Q15Assertion: Boiling point of (C_2 H_5)_2 NH is lower than that of n-C_4 H_9 NH_2. Reason (R): Hydrogen bonding is much…1 mk
• Q15Assertion: The solubility of aldehydes and ketones in water decreases with increase in size of the alkyl group. Reason…1 mk
• Q15Assertion: First ionisation enthalpy of Cr is lower than that of Zn. Reason (R): Zinc is a non-transition element.1 mk
• Q15Assertion: Aromatic primary amines cannot be prepared by Gabriel Phthalimide synthesis. Reason (R): Aryl halides do not…1 mk
• Q16Assertion (A): The boiling points of alkyl halides decrease in the order RI>RBr>RCl>RF. Reason (R): The van der Waals…1 mk
• Q16Assertion: Phenol is less acidic than alcohol. Reason (R): Phenoxide ion is more stable than alkoxide ion.1 mk
• Q16Assertion: The bond angle C - O - C in ethers is slightly greater than tetrahedral angle. Reason (R): This is because…1 mk
• Q16Assertion: Phenol is strongly acidic as compared to ethanol. Reason (R): Phenoxide ion is more stable than ethoxide ion.1 mk
• Q16Assertion: Maltose is a reducing sugar. Reason(R): One of the two glucose units can open to expose free aldehydic group…1 mk
• Q16Assertion: Vitamin D cannot be stored in our body. Reason (R): Vitamin D is fat soluble vitamin and is not excreted…1 mk
• Q16Assertion: Vitamin K can be stored in our body. Reason (R): Vitamin K is a water soluble vitamin.1 mk
• Q16Assertion: All naturally occurring α -amino acids except glycine are optically active. Reason (R): Most naturally…1 mk
• Q17Reactant 'A' underwent a decomposition reaction. The concentration of 'A' was measured periodically and recorded in the…2 mk
• Q17Give reasons: Cooking is faster in pressure cooker than in an open pan. On mixing liquid X and liquid Y, volume of the…2 mk
• Q17Define osmotic pressure. Why is measurement of osmotic pressure method preferred for the determination of molar masses…2 mk
• Q17The rate constant for a zero order reaction A → P is 0.0030 mol L^-1 s^-1. How long will it take for the initial…2 mk
• Q17State Raoult's law for a solution containing volatile components. Why is the vapour pressure of an aqueous solution of…2 mk
• Q17What is meant by negative deviation from Raoult's law? Give an example. What type of azeotrope is formed by negative…2 mk
• Q17What is meant by positive deviation from Raoult's law? Give an example. What type of azeotrope is formed by positive…2 mk
• Q17Calculate the elevation of boiling point of a solution when 3 g of CaCl_2(. Molar mass.=111 g mol^-1) was dissolved in…2 mk
• Q17State Henry's law. Why are aquatic species more comfortable in cold water as compared to warm water?2 mk
• Q17A and B liquids on mixing show rise in temperature. Which type of deviation from Raoult's law is there and why? Why can…2 mk
• Q18Why is molecularity applicable only for elementary reactions and order is applicable for elementary as well as complex…2 mk
• Q18Define the following terms: 2 × 1 Pseudo first order reaction Half-life period of reaction (t_1 / 2)2 mk
• Q18PtCl_4 · 2 KCl doesn't give precipitate of AgCl with AgNO_3 solution. Write the structural formula and IUPAC name of…2 mk
• Q18Observe the graph in the given figure and answer the following questions: Predict the order of reaction. What is the…2 mk
• Q18A reaction is of second order with respect to a reactant. How is the rate of reaction affected if the concentration of…2 mk
• Q18What is meant by the Rate law and Rate constant of a reaction. Identify the order of a reaction if the units of its…2 mk
• Q18Based on the data given above, give plausible reason for the variation of conductivity and molar conductivity with…2 mk
• Q18State a condition under which a bimolecular reaction is kinetically first order reaction. Give an example. For which…2 mk
• Q18Complete and balance the following chemical equations: 2 MnO_4^-(aq)+10 I^-(aq)+16 H^+(aq) → Cr_2 O_7^2-(aq)+6…2 mk
• Q18Write the structures of the main products of the following reactions:2 mk
• Q18When FeCr_2 O_4 is fused with Na_2 CO_3 in the presence of air it gives a yellow solution of compound. Compound on…2 mk
• Q19Draw the structures of product(s) in each of the following reactions:2 mk
• Q19Write the IUPAC name of the complex [Pt(en)_2 Cl_2]^2+. Draw the structure of geometrical isomer of this complex which…2 mk
• Q19Complete and balance the following chemical equations: 2 × 1 8 MnO_4^-+3 S_2 O_3^2-+H_2 O → Cr_2 O_7^2-+3 Sn^2++14 H^+ →2 mk
• Q19When FeCr_2 O_4 is fused with Na_2 CO_3 in the presence of air it gives a yellow solution of compound. Compound on…2 mk
• Q19Write the rate law expression for the reaction 2 HI → H_2+I_2, if the order of the reaction is zero. What is the effect…2 mk
• Q19Name and define the cell which was used for providing electric power in the Apollo space programme. Also write its one…2 mk
• Q19Examine the following observations: 2 × 1 Transition elements generally form coloured compounds. Zinc is not regarded…2 mk
• Q19Would you expect benzaldehyde to be more reactive or less reactive in nucleophilic addition reactions than propanal?…2 mk
• Q19Define fuel cell. Give two advantages of fuel cell over ordinary cell.2 mk
• Q19Write IUPAC names of the following coordination compounds: (i) [CoCl_2(en)_2] SO_4 (ii) K_3[Fe(C_2 O_4)_3] OR…2 mk
• Q19Define rate constant. Identify the reaction order which has a rate constant of 4 · 5 × 10^-5 L mol^-1 s^-1.2 mk
• Q19Give any two differences between order and molecularity of a reaction. For a reaction X+Y → Z, in which both X and Y…2 mk
• Q20Why are haloarenes less reactive towards nucleophilic substitution reaction? How does the presence of nitro (-NO_2)…2 mk
• Q20Identify A and B in each of the following reaction sequence: CH_3 CH_2 Cl →NaCN A →H_2 / Ni B C_6 H_5 NH_2 →[0-5^°…2 mk
• Q20Write the mechanism of dehydration of ethyl alcohol with conc. H_2 SO_4 at 443 K.2 mk
• Q20Write the mechanism of dehydration of ethyl alcohol with conc. H_2 SO_4 at 413 K.2 mk
• Q20Explain [Co(NH_3)_6]^3+ is an inner orbital complex whereas [Ni(NH_3)_6]^2+ is an outer orbital complex. [At. No.…2 mk
• Q20Write two differences between Amylose and Amylopectin components of starch.2 mk
• Q20Draw the structures of major monohalo products in each of the following reactions:2 mk
• Q20PdCl_2 · 2 KCl does not give precipitate of AgCl with AgNO_3 solution. Write the structural formula and IUPAC name of…2 mk
• Q20Name the following coordination compounds according to IUPAC norms: 2 × 1 [Co(NH_3)_4(H_2 O) C l] C l_2 [CrCl_2(en)_2]…2 mk
• Q20Explain the mechanism of acid catalysed hydration of ethene.2 mk
• Q20Write the structures of the main products of the following reactions:2 mk
• Q21Give a simple chemical test to distinguish between 3-pentanone and 2-pentanone. Write an equation for Clemmensen…2 mk
• Q21Give reasons for the following: The melting points of α -amino acids are generally higher than that of the…2 mk
• Q21What are the hydrolysis products of: 2 Sucrose Lactose2 mk
• Q21In the following pair of halogen compounds, which compound undergoes S_N 1 reaction faster and why? Arrange the…2 mk
• Q21Write the reactions involved when D-glucose is treated with the following reagents: (1+1=2) HCN Br_2 water2 mk
• Q21Write the structures of the main products of the following reactions:2 mk
• Q21What is meant by essential amino acids? Why are amino acids amphoteric in nature?2 mk
• Q21The two strands in DNA are not identical but complementary. Explain. What products would be formed when DNA is…2 mk
• Q21Give reasons for the following observations: 1 + 1 p-Chloronitrobenzene reacts with (aq) NaOH at 443 K to give…2 mk
• Q21The reaction between A_2( g) and B_2( g) was carried out in a sealed isothermal container. The rate law for the…2 mk
• Q21How do you explain the following? Presence of an aldehydic group in glucose. Presence of five - OH groups in glucose.2 mk
• Q21Draw the structures of the major monohalo products in each of the following reactions:2 mk
• Q21How can acetaldehyde be prepared from acetyl chloride? Propanal is more reactive than propanone towards nucleophilic…2 mk
• Q21Carboxylic acid is more acidic than phenol. Give reason. Give a chemical test to distinguish between benzaldehyde and…2 mk
• Q22A solution of glucose (molar mass =180 g mol^-1 ) in water has a boiling point of 100.20^° C. Calculate the freezing…3 mk
• Q22Shweta mixed two liquids A and B of 10 mL each. After mixing, the volume of the solution was found to be 20 · 2 mL. (i)…3 mk
• Q22Henry's law constant for CO_2 in water is 1.67 × 10^8 Pa at 298 K. Calculate the number of moles of CO_2 in 540 g of…3 mk
• Q22At 25 °C the saturated vapour pressure of water is 24 mm Hg. Find the saturated vapour pressure of a 5% aqueous…3 mk
• Q22Differentiate between: Essential amino acids and Non-essential amino acids Peptide linkage and Glycosidic linkage…3 mk
• Q22Can sodium methoxide and t-butyl bromide be used for the preparation of t-butyl methyl ether. Give suitable reason.…3 mk
• Q22How can you obtain the following from aniline? Give only chemical equation. p -nitroaniline Chlorobenzene Phenol3 mk
• Q22How can you obtain the following? Aniline from ammonium benzoate Benzene diazonium chloride from nitrobenzene…3 mk
• Q22Account for the following: (i) Allyl chloride is hydrolysed more readily than n-propyl chloride. (ii) Isocyanides are…3 mk
• Q22A solution containing 15 g urea (molar mass =60 g mol^-1 ) per litre of solution in water has the same osmotic pressure…3 mk
• Q22Henry's law constant for CO_2 in water is 1.67 × 10^8 Pa at 298 K. Calculate the number of moles of CO_2 in 500 ml of…3 mk
• Q23Calculate the cell voltage of the voltaic cell which is set up by joining following half-cells at 25^° C: Al / Al^3+(0…3 mk
• Q23Calculate Δ_r G^° and log K_C of the reaction: Fe^2+(aq)+Ag^+(aq) → Fe^3+(aq)+Ag(s) Given E_Ag^+ / Ag^°=0.80 V, E_Fe^3+…3 mk
• Q23Calculate Λ^° m for acetic acid and its degree of dissociation (α) if its molar conductivity is 48.1 Ω^-1 cm^2 mol^-1.…3 mk
• Q23Give reasons: Fuel cells are preferred for production of electrical energy than thermal plants. Iron does not rust even…3 mk
• Q23Calculate Δ_r G^° and log K_C of the reaction. 3 2 Cr( s)+3 Cd^2+(aq) → 2 Cr^3+(aq)+3 Cd( s) Given E_Cr^3+ / Cr^°=-0.74…3 mk
• Q23State the following: 3 (i) Kohlrausch law of independent migration of ions and (ii) Faraday's first law of…3 mk
• Q23For the reaction A+B → Products, the following initial rates were obtained at various initial concentrations of…3 mk
• Q23Arrange the following compounds as asked: in increasing order of pK_b values C_2 H_5 NH_2,(C_2 H_5)_2 NH, C_6 H_5…3 mk
• Q23The electrical resistance of a column of 0.05 M NaOH solution of area 0.8 cm^2 and length 40 cm is 5 × 10^3 ohm.…3 mk
• Q23The rate of a reaction: A+B → product is given below as a function of different initial concentrations of A and B.…3 mk
• Q24Give reasons for the following: The pH of aqueous NaCl increases when it is electrolysed. Unlike dry cell, mercury cell…3 mk
• Q24The following data were obtained during the first order thermal decomposition of N_2 O_5( g) at constant volume: 2 N_2…3 mk
• Q24Of the d^4 species, Cr^2+ is strongly reducing while Mn^3+ is strongly oxidising. Why? Write two consequences of…3 mk
• Q24Calculate the cell voltage of the voltaic cell which is set up by joining the following half-cells at 25°C: Al /…3 mk
• Q24What is meant by crystal field splitting energy? For a d^4 ion, write the configuration if (i) Δ_o<P, and (ii) Δ_o>P.…3 mk
• Q24E_(Mn^2+ / Mn)^° is -1.18 V. Why is this value highly negative in comparison to neighbouring d-block elements? What is…3 mk
• Q24A certain reaction is 50% complete in 20 minutes at 300 K and the same reaction is 50% complete in 5 minutes at 350 K.…3 mk
• Q24Write structure of the products of the following reactions: conc. HNO_3 →3 mk
• Q24Write the name and structure of a hexadentate ligand. 1 Why is [Ni(CN)_4]^2- square planar while [Ni(CO)_4] is…3 mk
• Q24Based on Valence Bond Theory, explain the geometry and magnetic character of [NiCl_4]^2-. [Atomic number: Ni=28 ] Draw…3 mk
• Q24Complete and balance the following chemical equations: 3 × 1 MnO_4^-+C_2 O_4^2-+H^+ → KMnO_4 →[513 K] Heat Cr_2…3 mk
• Q24Arrange the following in decreasing order of pK_b: Aniline, p-nitroaniline, p-methylaniline Account for the following:…3 mk
• Q24The rate of a reaction quadruples when the temperature changes from 293 K to 313 K. Calculate the energy of activation…3 mk
• Q25Using valence bond theory, explain the hybridization and magnetic character of the following: 2 × 1 1/2=3…3 mk
• Q25An aqueous solution of NaOH was made and its molar mass from the measurement of osmotic pressure at 27^° C was found to…3 mk
• Q25Write any two differences between S_N 1 and S_N 2 reactions. Which of the following compounds would undergo S_N 1…3 mk
• Q25A compound with molecular formula C_4 H_9 I which is a primary alkyl halide, reacts with alcoholic KOH to give…3 mk
• Q25The elements of 3d transition series are given as: Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn Answer the following: Copper…3 mk
• Q25Answer the following about the complexes [FeF_6]^3- and [Fe(CN)_6]^4-: (i) Write the hybridization involved in each…3 mk
• Q25Account for the following: Haloarenes are less reactive towards nucleophilic substitution reactions. p -dichlorobenzene…3 mk
• Q25Among the following, which will have inversion of configuration on reaction with aqueous alkali and why? (i)…3 mk
• Q25Write IUPAC names of the following coordination entities: [Fe(en)_2 Cl_2]^+ [Co(NH_3)_4(H_2 O) Br] SO_4 [Ni(CN)_4]^2-3 mk
• Q25Vapour pressure of pure water at 298 K is 24.8 mm Hg. Calculate the lowering in vapour pressure of an aqueous solution…3 mk
• Q25Using valence bond theory, explain the hybridization and magnetic behaviour of the following: 2+1=3 (i) [Co(NH_3)_6] C…3 mk
• Q25Account for the following: The C - Cl bond length in chlorobenzene is shorter than that in methyl chloride. Grignard…3 mk
• Q26Define the following: 2+1=3 (i) Enantiomers (ii) Racemic mixture Why is chlorobenzene resistant to nucleophilic…3 mk
• Q26Write the chemical equation for Williamson's synthesis. Give a method to separate o -nitrophenol and p -nitrophenol.…3 mk
• Q26Arrange the following compounds as asked: in decreasing order of pK_b values C_2 H_5 NH_2,(C_2 H_5)_2 NH, C_6 H_5…3 mk
• Q26Write the chemical equation for the following: (i) Preparation of phenol from cumene (ii) Nitration of anisole Complete…3 mk
• Q26Arrange the following compounds in the increasing order of their acidic strength: 3,5-dinitrophenol, 4-methylphenol,…3 mk
• Q26Can sodium propoxide and t-butyl chloride be used for the preparation of t-butyl propyl ether? Give suitable…3 mk
• Q26Write structure of the products of the following reactions:3 mk
• Q26Give explanation for each of the following observations: With the same d-orbital configuration (d^4), Mn^3+ ion is an…3 mk
• Q26Draw the structure of the major monohalo product for each of the following reaction: (1+1+1=3) How do you convert:…3 mk
• Q27Write the products formed in the following reactions: CH_3 CHO+NH_2 CONHNH_2 → 1 CH_3 CHO → dil. NaOH 1 CH_3 COOH →[H_2…3 mk
• Q27Explain the following reactions and write chemical equation involved: Wolff-Kishner reduction Etard reaction Cannizzaro…3 mk
• Q27An aromatic compound 'A' with molecular formula C_8 H_8 O gives positive 2,4-DNP test. It gives yellow precipitate. of…3 mk
• Q27An aqueous solution of NaOH was made and its molar mass from the measurement of osmotic pressure at 25^° C was found to…3 mk
• Q27Give reasons for the following: Benzoic acid does not undergo Friedel-Crafts reaction. HCHO is more reactive than CH_3…3 mk
• Q27Write the name of the cell which is generally used in inverters. Write the reactions taking place at anode and cathode…3 mk
• Q27Identify P, Q and R in the following reaction sequence: P →NH_3 CH_3 COO^- NH_4^+ →Δ Q; PCl_5 R3 mk
• Q27Arrange the following compounds in increasing order of their boiling point: (1+2=3) (CH_3)_2 NH, CH_3 CH_2 NH_2, CH_3…3 mk
• Q27A compound with molecular formula C_4 H_5 N on reduction with DIBAL-H followed by hydrolysis, gives a compound.…3 mk
• Q27An organic compound 'A' (molecular formula C_8 H_8 O ) gives 2,4-DNP test. It does not give Tollen's test, but gives a…3 mk
• Q27Write structure of the products of the following reactions:3 mk
• Q28Can sodium ethoxide and t-butyl chloride be used for the preparation of t-butyl ethyl ether? Give suitable explanation.…3 mk
• Q28Calculate the cell voltage of the voltaic cell which is set up by joining the following half-cells at 25°C. Al /…3 mk
• Q28Define the following terms: Glycosidic linkage Invert sugar Oligosaccharides3 mk
• Q28Write the reaction of D-Glucose with the following: HCN Br_2 water (CH_3 CO)_2 O3 mk
• Q28Define the following terms: Native protein Nucleotide Essential amino acid3 mk
• Q28Write the reaction when D-glucose reacts with the following: (i) NH_2 OH (ii) Acetic anhydride Why vitamin C cannot be…3 mk
• Q28Name the type of linkage responsible for the formation of proteins from α -amino acids. Write any two differences…3 mk
• Q28How will you obtain the following from aniline? Give chemical equations only. Sulphanilic acid Phenylisocyanide…3 mk
• Q28Name the vitamin which is responsible for coagulation of blood. 1 What is meant by denaturation of protein? Give an…3 mk
• Q28Name the vitamin whose deficiency causes pernicious anaemia. Write any two differences between globular and fibrous…3 mk
• Q28A compound 'A' with molecular formula C_4 H_8 O gives positive 2,4-DNP test. It gives yellow precipitate of compound…3 mk
• Q28What is the difference between native protein and denatured protein? (1+1+1=3) Which one of the following is a…3 mk
• Q28Write the product obtained when D-glucose reacts with H_2 N-OH. Amino acids show amphoteric behaviour, why? Why vitamin…3 mk
• Q29Carbohydrates are polyhydroxy aldehydes or ketones that represent enormous structural diversity in terms of the…4 mk
• Q29The Crystal Field Theory (CFT) of coordination compounds is based on the effect of different crystal fields (provided…4 mk
• Q29Phenols undergo electrophilic substitution reactions readily due to the strong activating effect of OH group attached…4 mk
• Q29The rate of a chemical reaction is expressed either in terms of decrease in the concentration of reactants or increase…4 mk
• Q29The spontaneous flow of the solvent through a semipermeable membrane from a pure solvent to a solution or from a dilute…4 mk
• Q29Alcohols undergo a number of reactions involving the cleavage of C - OH bond. However, phenols do not undergo reactions…4 mk
• Q29According to the generally accepted definition of the ideal solution there are equal interaction forces acting between…4 mk
• Q30Amines have a lone pair of electrons on nitrogen atom due to which they behave as Lewis base. Greater the value of K_b…4 mk
• Q30Amines are usually formed from amides, imides, halides, nitro compounds, etc. They exhibit hydrogen bonding which…4 mk
• Q30The α -amino acids are the building blocks of proteins. All α -amino acids exist as zwitter ion due to which they show…4 mk
• Q30Ribose and 2-deoxyribose have an important role in biology. Among the most important derivatives are those with…4 mk
• Q30Werner's coordination theory in 1893 was the first attempt to explain the bonding in coordination complexes. It must be…4 mk
• Q31(i) For a galvanic cell, the following half reactions are given. Decide, which will remain as reduction reaction and…5 mk
• Q31(i) Complete the following reactions by writing the structure of the main products: (II) (CH_3) _2 Cd+2 CH_3 COCl →…5 mk
• Q31Give IUPAC name of CH_3-CH=CH-CHO. Give a simple chemical test to distinguish between propanal and propanone. How will…5 mk
• Q32(i) Calculate E_cell of a galvanic cell in which the following reaction takes place at 25^° C: Zn( s)+Pb^2+(0 · 02 M) →…5 mk
• Q32(i) In a chemistry practical class, the teacher gave his students an amine 'X' having molecular formula C_2 H_7 N, and…5 mk
• Q32For the complex [Fe(en)_2 C l_2] C l, identify: 5 the oxidation number of iron. the hybridization and the shape of the…5 mk
• Q32(i) Give reasons: (I) [Ni(CO)_4] is diamagnetic whereas [NiCl_4]^2- is paramagnetic. [Atomic number: Ni = 28] (II) CO…5 mk
• Q32Give IUPAC name of CH_3-CH=CH-CHO. Give a simple chemical test to distinguish between propanal and propanone. 1 How…5 mk
• Q32(i) Account for the following: (I) Orange colour of Cr_2 O_7^2- ion changes to yellow when treated with an alkali. (II)…5 mk
• Q32Answer the following: Low spin tetrahedral complexes are not known. Co^2+ is easily oxidised to Co^3+ in the presence…5 mk
• Q32Calculate the standard Gibbs energy (Δ_r G^°) of the following reaction at 25 °C: 3 + 2 Au(s)+Ca^2+(1 M) → Au^3+(1…5 mk
• Q32In the following complex ions, explain the type of hybridisation, shape and magnetic property: (2 1/2 × 2=5) [Fe(H_2…5 mk
• Q33Calculate the standard Gibbs energy (Δ_r G^°) of the following reaction at 25 °C: 3 + 2 Au( s)+Ca^2+(1 M) → Au^3+(1…5 mk
• Q33(i) Identify A, B and C in the following reactions: (ii) Give reasons for the following: (I) Carboxylic acids do not…5 mk
• Q33(i) When pyrolusite ore is fused with KOH, in presence of air, a dark green coloured product 'A' is obtained which…5 mk
• Q33Write the cell reaction and calculate the e.m.f. of the following cell at 298 K: ( 3 + 2 = 5 ) Sn(s)|Sn^2+(0.004…5 mk
• Q33(i) An organic compound (X) having molecular formula C_5 H_10 O can show various properties depending on its…5 mk
• Q33Carry out the following conversions: (2+3=5) (i) Ethanal to But-2-enal (ii) Propanoic acid to ethane An alkene A with…5 mk
• Q33(i) Calculate the emf of the following cell at 25°C: Zn(s)|Zn^2+(0.1 M)||H^+(0.01 M)| H_2( g) (1 bar), Pt(s) [ Given:…5 mk
• Q33(i) Account for the following: (I) The E_Mn^2+ / Mn^° value for manganese is highly negative, whereas E_Mn^3+ / Mn^2+^°…5 mk
• Q33(i) The initial concentration of N_2 O_5 in the first order reaction: N_2 O_5( g) → 2 NO_2( g)+1/2 O_2( g) was 1 · 2 ×…5 mk
• Q33An organic compound 'A', molecular formula C_2 H_6 O oxidises with CrO_3 to form a compound 'B'. Compound 'B' on…5 mk