CBSE Class 12 Chemistry 2023

What 2023 actually asked, chapter by chapter

Marks we counted in the 2023 papers themselves. CBSE allocates marks per unit, not per chapter — this is what was observed, not an official CBSE weightage.

All 322 questions from 2023

• Q1A compound undergoes complete tetramerization in a given organic solvent. The Van't Hoff factor ' i ' is:1 mk
• Q1Which of the following molecules has a chiral centre correctly labelled with an asterisk ( )?1 mkasked 2×
• Q1The colligative property used for the determination of molar mass of polymers and proteins is:1 mkasked 3×
• Q1A compound CaCl 2 · 6 H 2 O undergoes complete dissociation in water. The Van't Hoff factor 'i' is:1 mk
• Q1On dissolving ammonium chloride in water at room temperature, the solution feels cool to touch. Under which of the…1 mk
• Q1A compound undergoes complete dimerization in a given organic solvent. The Van't Hoff factor ' i ' is:1 mk
• Q1Which of the following has the highest melting point?1 mk
• Q1Auto oxidation of chloroform in air and sunlight produces a poisonous gas known as1 mk
• Q1Which of the following is not true about enantiomers?1 mk
• Q1The conversion of an alkyl halide into an alkene by alcoholic KOH is classified as1 mk
• Q1Which of the following belongs to the class of Vinyl halides?1 mk
• Q2Sodium phenoxide when heated with CO 2 under pressure, followed by acidification, yields:1 mk
• Q2Which of the following alcohols will not undergo oxidation?1 mkasked 3×
• Q2Lanthanoid contraction is due to increase in:1 mk
• Q2What is the secondary valency of Cobalt in [Co(en 2) Cl 2]^+? 11 mk
• Q2The half-life for a zero order reaction equals:1 mk
• Q2Which of the following belongs to the class of alkyl halides?1 mk
• Q2Which of the following ligands is an ambidentate ligand?1 mk
• Q2Aspirin is obtained by the acetylation of which of the following compounds?1 mk
• Q2For the reaction A+2 B → C+D, the rate law is given by r=k[A][B]^2, the concentration of A is kept constant while that…1 mk
• Q2Low concentration of oxygen in the blood and tissues of people living at high altitude is due to:1 mkasked 2×
• Q2The oxidation state of Fe in [Fe(CO) 5] is1 mk
• Q2For a zero order reaction of the type A → products, the rate equation may be expressed as:1 mk
• Q3Which of the following structures represents α -D-glucose?1 mkasked 3×
• Q3A compound with molecular formula C 5 H 10 O, forms a phenyl hydrazone and gives negative Tollens'and iodoform tests.…1 mk
• Q3Consider the following standard electrode potential values: Fe^3+ (aq)+e^- → Fe^2+ (aq) E^°=+0.77 V MnO 4^- (aq)+8…1 mk
• Q3Consider the following standard electrode potential values: Sn^2+ (aq)+2 e^- → Sn (s) E^°=-0.14 V Fe^3+ (aq)+e^- →…1 mk
• Q3The correct cell to represent the following reaction is: Zn+2 Ag^+ → Zn^2++2 Ag1 mkasked 2×
• Q3Ag^+(aq)+e^- → Ag(s) E^°=+0.80 V Fe^2+(aq)+2 e^- → Fe(s) E^°=-0.44 V Find the E cell^° for: Fe(s)+2 Ag^+(aq) →…1 mk
• Q3A voltaic cell is made by connecting two half cells represented by half equations below: Sn^2+ (aq)+2 e^- → Sn (s)…1 mkasked 2×
• Q3The reactivities of the carbonyl compounds HCHO (I), CH 3 CHO (II) and CH 3 COCH 3 (III) towards nucleophilic addition…1 mk
• Q3When Benzene diazonium chloride reacts with phenol, it forms a dye. This reaction is called1 mk
• Q3Which of the following Cu^2+ halide is not known?1 mk
• Q3Among the following, which is the strongest base?1 mk
• Q3Among the following, which has the highest value of p^K b?1 mk
• Q4The slope in the plot of [R] vs. time for a zero order reaction is1 mk
• Q4Four half reactions I to IV are shown below: I. 2 Cl l^- → Cl 2+2 e^- II. 4 OH^- → O 2+2 H 2 O+2 e^- III. Na^++e^- → Na…1 mkasked 3×
• Q4The slope in the plot of ln [R] vs. time for a first order reaction is 11 mk
• Q4The slope in the plot of log ([R] 0)/([R]) vs. time for a first order reaction is1 mk
• Q4The interstitial compounds of transition metals are1 mk
• Q4For the conversion of propene into 1-propanol, which of the following reagents and conditions should be used?1 mk
• Q4The ions of metals of Group 12 (Zn, Cd and Hg) have completely filled d orbitals and so they:1 mk
• Q4Benzene diazonium chloride on hydrolysis gives:1 mk
• Q4Δ G and E cell^° for a spontaneous reaction will be:1 mkasked 2×
• Q4A first order reaction takes 30 minutes for 50 % completion. The value of rate constant k would be:1 mk
• Q5Helical structure of proteins is stabilized by:1 mk
• Q5On hydrolysis, which of the following carbohydrates gives only glucose?1 mk
• Q5The compounds [Cr(H 2 O) 6] Cl 3,[Cr(H 2 O) 5 Cl] Cl 2 · H 2 O and [Cr(H 2 O) 4 Cl 2] Cl.2 H 2 O exhibit:1 mk
• Q5Which of the following reagents would one choose to transform CH 3 COCl into acetone?1 mk
• Q5[Co(NH 3) 5 NO 3] SO 4 and [Co(NH 3) 5 SO 4] NO 3 exhibit:1 mk
• Q5What type of isomerism is shown by the following pair of complex compounds? [Co(NH 3) 6][Cr(CN) 6] and [Cr(NH 3)…1 mk
• Q5Which of the following is affected by catalyst?1 mkasked 3×
• Q5Which property of transition metals enables them to behave as catalysts?1 mkasked 3×
• Q5When D-glucose reacts with HI, it forms1 mk
• Q5Proteins are polymers of1 mk
• Q6Which of the following is least basic?1 mkasked 3×
• Q6Reaction of 1-phenyl-2-chloropropane with alcoholic KOH gives mainly:1 mkasked 3×
• Q6A vitamin which plays a vital role in the clotting of blood is:1 mk
• Q6Retention of configuration is observed in1 mk
• Q6Racemisation occurs in 11 mk
• Q6The order of the reaction H 2( g)+Cl 2( g) h ν 2 HCl( g) is:1 mkasked 2×
• Q6Which of the following vitamins is water soluble?1 mk
• Q6The reaction of ammonia with a large excess of methyl chloride will yield mainly:1 mk
• Q6In the two tetrahedral structures of dichromate ion1 mk
• Q6The unit of molar conductivity is1 mk
• Q6Which of the following alkenes on acid catalysed hydration gives a tertiary alcohol?1 mk
• Q6Which of the following ions has the electronic configuration 3 d^6? (Atomic number: Mn=25, Co=27, Ni=28 )1 mk
• Q6Inversion of configuration occurs in1 mk
• Q7Value of Henry's constant K H:1 mk
• Q7When nitrobenzene is heated with tin and concentrated HCl, the product formed is:1 mk
• Q7Which of the following aqueous solution will have highest boiling point?1 mk
• Q7The most common and stable oxidation state of a Lanthanoid is:1 mkasked 3×
• Q7The product formed in the reaction: is1 mk
• Q71 mole of liquid A and 2 moles of liquid B make a solution having a total vapour pressure 40 torr. The vapour pressure…1 mk
• Q7Solubility of gas in liquid decreases with increase in1 mk
• Q7When diethyl ether is heated with excess of HI, it produces:1 mk
• Q7In the ring structure of glucose, the anomeric carbon is:1 mk
• Q7An azeotropic mixture of two liquids will have a boiling point lower than either of the two liquids when it1 mk
• Q7The rate of reaction A+B → Products, is given by the equation r=k[A] [B]. If B is taken in large excess, the order of…1 mk
• Q7Out of the following 1.0 M aqueous solutions, which one will show largest freezing point depression?1 mk
• Q7The unit of the rate of reaction is the same as that of the rate constant for a:1 mk
• Q8The action of nitrous acid on ethylamine gives mainly:1 mk
• Q8Which of the following would not be a good choice for reducing nitrobenzene to aniline?1 mkasked 2×
• Q8Deficiency of Vitamin B causes:1 mk
• Q8The reduction of ethanenitrile with sodium and alcohol gives:1 mk
• Q8Which of the following solutions of KC l will have the highest value of molar conductivity?1 mkasked 2×
• Q8Which of the following relations is incorrect?1 mk
• Q8The compounds [Co(SO 4)(NH 3) 5] Br and [Co(Br)(NH 3) 5] SO 4 represent:1 mkasked 3×
• Q9The species that attacks benzene in following is:1 mk
• Q9Amides can be converted into amines by the reaction named1 mk
• Q9The reagent that can be used to distinguish acetophenone and benzophenone is1 mk
• Q9The synthesis of alkyl fluoride is best obtained from:1 mkasked 2×
• Q9An azeotropic mixture of two liquids has a boiling point higher than either of the two liquids when it:1 mkasked 3×
• Q9If molality of a dilute solution is doubled, the value of the molal elevation constant (K b) will be1 mk
• Q9In the reaction C 6 H 5 NH 2+CHCl 3+3 KOH → A+3 B+3 C the product A is1 mk
• Q9Corrosion of iron is:1 mk
• Q9The number of faradays passed through a solution of CuSO 4 to produce 1 mol of Cu and O 2 will be:1 mk
• Q9Which of the following reactions are feasible?1 mkasked 3×
• Q9How many Faradays are required to reduce 1 mol of MnO 4^- to Mn^2+?1 mk
• Q9Which of the following does not give Cannizaro reaction?1 mk
• Q10In a reaction, the initial concentration of the reactants increases four fold and the rate becomes sixteen times its…1 mk
• Q10Which of the following statements is not true about glucose?1 mk
• Q10β -pleated sheet structure in proteins refers to1 mk
• Q10If the initial concentration is reduced to 1/4 th in a zero order reaction, then the time taken for half the reaction…1 mk
• Q10Which one of the following pairs will not form an ideal solution?1 mk
• Q10The number of molecules that react with each other in an elementary reaction is a measure of the:1 mk
• Q10Isotonic solutions have:1 mk
• Q10Hydrolysis of sucrose is called1 mk
• Q10Which of the following is most reactive in nucleophilic addition reactions?1 mk
• Q11Among the following outermost configurations of transition metals which one shows the highest oxidation state?1 mk
• Q11On hydrolysis, which of the following carbohydrates gives only glucose?1 mk
• Q11Which of the following does not give aldol condensation reaction?1 mk
• Q11CH 3 CONH 2 on reaction with NaOH and Br 2 in alcoholic medium gives:1 mkasked 3×
• Q11Aldehydes and ketones react with hydroxylamine to form 11 mk
• Q11The half-life of a reaction is doubled when the initial concentration is doubled. The order of the reaction is:1 mk
• Q11On hydrolysis, which of the following carbohydrates gives glucose and galactose?1 mk
• Q11On hydrolysis, which of the following carbohydrates gives glucose and fructose?1 mk
• Q11Which one of the following has lowest pK a value?1 mkasked 2×
• Q11KMnO 4 acts as an oxidising agent in alkaline medium. When alkaline KMnO 4 is treated with KI, iodide ion is oxidised…1 mk
• Q11Which of the following compounds will undergo self-condensation in the presence of dilute NaOH solution?1 mk
• Q12For a reaction 2 A → 3 B, rate of reaction -(d[A])/(dt) is equal to 11 mk
• Q12The deficiency of which of the following vitamins causes Scurvy?1 mk
• Q12Deficiency of which of the following vitamins causes Pernicious anaemia?1 mk
• Q12Which of the following transition metals does not show variable oxidation state?1 mk
• Q12For the reaction 3 A → 2 B, rate of reaction +(d[B])/(dt) is equal to1 mkasked 2×
• Q12Which of the following ions has the maximum number of unpaired d-electrons?1 mk
• Q12The deficiency of which of the following vitamins causes 'Rickets'?1 mk
• Q12How many ions are produced in the solution from the complex [Ni(NH 3) 6] Cl 2?1 mk
• Q12For the reaction 3 A → 2 B, rate of reaction -(d[A])/(dt) is equal to1 mk
• Q12Which of the following cell was used in Apollo space programme?1 mkasked 3×
• Q13This reaction is known as:1 mk
• Q13Which of the following species is not expected to be a ligand?1 mk
• Q13Which of the following is a polydentate ligand?1 mk
• Q13Which of the following complexes is a'chelate'complex?1 mk
• Q13The glycosidic linkage involved in linking the glucose units in amylase part of starch is:1 mkasked 3×
• Q13Which of the following characteristics of transition metals is associated with their catalytic activity?1 mk
• Q13C 6 H 5 CHO+CH 3 COCH 3 [Δ]OH^- C 6 H 5 CH=CH-COCH 3 This reaction is known as:1 mk
• Q13Which of the following is an 'Acetal'?1 mk
• Q13The following experimental rate data were obtained for a reaction carried out at 25 °C: A (g)+B (g) → C (g)+D (g) What…1 mkasked 3×
• Q14In which of the following does the central atom exhibit an oxidation state of+3?1 mk
• Q14Which one among the following metals of 3d series has the lowest melting point?1 mk
• Q14The formula of the complex Iron (III) hexacyanidoferrate (II) is:1 mk
• Q14The formula of the complex dichloridobis (ethane -1,2 -diamine) platinum (IV) nitrate is1 mkasked 2×
• Q14The crystal field splitting energy in tetrahedral crystal field (Δ t) is equal to:1 mk
• Q14Optical isomerism is not shown by the complex:1 mk
• Q14The magnetic moment of [NiCl 4]^2-1 mk
• Q14An α -helix is a structural feature of:1 mk
• Q14Which of the following is the most stable complex species?1 mk
• Q14Which of the following coordination compounds exhibits linkage isomerism?1 mk
• Q14Which of the following is a non-reducing sugar?1 mk
• Q14In which of the following does the central atom exhibit an oxidation state of +4?1 mk
• Q15Assertion: Osmotic pressure is a colligative property. Reason (R): Osmotic pressure is proportional to the molality.1 mk
• Q15Assertion: (C 2 H 5) 2 NH is more basic than (C 2 H 5) 3 N in aqueous solution. Reason (R): In (C 2 H 5) 2 NH, there is…1 mk
• Q15Assertion: Order and molecularity of a reaction are always same. Reason (R): Complex reactions involve a sequence of…1 mkasked 3×
• Q15Assertion: Proteins are polymers of α -amino acids connected by a peptide bond. Reason (R): A tetrapeptide contains 4…1 mk
• Q15Assertion: When NaCl is added to water, a depression in freezing point is observed. Reason (R): The vapour pressure of…1 mk
• Q15Assertion: Vitamin C cannot be stored in our body. Reason (R): Vitamin C is fat soluble and is excreted from the body…1 mk
• Q15Assertion:-NH 2 group is o -and p -directing in electrophilic substitution reactions. Reason (R): Aniline cannot…1 mk
• Q15Assertion: Ammonolysis of alkyl halides is not a suitable method for the preparation of pure primary amines. Reason…1 mk
• Q15Assertion: When glucose is added to water, an elevation in boiling point is observed. Reason (R): The lowering of…1 mk
• Q15Assertion: The enthalpy of mixing Δ mix H is equal to zero for an ideal solution. Reason (R): For an ideal solution the…1 mk
• Q15Assertion: The backbone of DNA and RNA molecules is a chain consisting of heterocyclic base, pentose sugar and…1 mk
• Q15Assertion: Elevation in boiling point is a colligative property. Reason (R): The lowering of vapour pressure of…1 mk
• Q15Assertion: When NaCl is added to water, a depression in freezing point is observed. Reason (R): The lowering of vapour…1 mk
• Q16Assertion: Order of reaction is applicable to elementary as well as complex reactions. Reason (R): For a complex…1 mk
• Q16Assertion: Λ m for weak electrolytes shows a sharp increase when the electrolytic solution is diluted. Reason (R): For…1 mk
• Q16Assertion: Electrolysis of aqueous solution of NaCl gives chlorine gas at anode instead of oxygen gas. Reason (R):…1 mkasked 2×
• Q16Assertion: Molar conductivity decreases with increase in concentration. Reason (R): When concentration approaches zero,…1 mk
• Q16Assertion: For a zero order reaction the unit of rate constant and rate of reaction are same. Reason (R): Rate of…1 mkasked 4×
• Q16Assertion: Λ m for weak electrolytes shows a sharp decrease when the electrolytic solution is diluted. Reason (R): For…1 mk
• Q16Assertion: Chlorobenzene is resistant to electrophilic substitution reaction. Reason (R): C-Cl bond in chlorobenzene…1 mk
• Q16Assertion: Acetylation of aniline gives a monosubstituted product. Reason (R): Activating effect of -NHCOCH 3 group is…1 mkasked 3×
• Q16Assertion: Conductivity decreases with decrease in concentration of electrolyte. Reason (R): Number of ions per unit…1 mkasked 2×
• Q16Assertion: The half life of a reaction is the time in which the concentration of the reactant is reduced to one half of…1 mk
• Q17Assertion: Bromination of benzoic acid gives m-bromobenzoic acid. Reason (R): Carboxyl group increases the electron…1 mk
• Q17Assertion: Acetic acid but not formic acid can be halogenated in presence of red P and C l 2. Reason (R): Acetic acid…1 mk
• Q17Assertion: Transition metals show their highest oxidation state with oxygen. Reason (R): The ability of oxygen to form…1 mkasked 2×
• Q17Assertion: Copper is a non-transition element. Reason (R): Copper has completely filled d-orbitals in its ground state.1 mk
• Q17Assertion: Limiting molar conductivity (Λ m^°) is obtained by the extrapolation of the Λ m versus C^1 / 2 curve of…1 mk
• Q17Assertion: The molecularity of the reaction H 2+Br 2 → 2 HBr appears to be 2. Reason (R): Two molecules of the…1 mkasked 3×
• Q17Assertion: Zr and Hf have almost identical radii. Reason (R): Both Zr and Hf exhibit similar properties.1 mk
• Q17Assertion: The final product in Aldol condensation is always α, β - unsaturated carbonyl compound. Reason (R): α, β…1 mk
• Q17Assertion: Nucleophilic substitution of iodoethane is easier than chloroethane. Reason (R): Bond energy of C - Cl bond…1 mkasked 3×
• Q18Assertion: EDTA is a hexadentate ligand. Reason (R): EDTA has 2 nitrogen and 4 oxygen donor atoms.1 mk
• Q18Assertion: Transition metals have high enthalpy of atomisation. Reason (R): Greater number of unpaired electrons in…1 mk
• Q18Assertion: Manganese shows the highest oxidation state of +7 in 3d series. Reason (R): Transition metals show variable…1 mk
• Q18Assertion: Low spin tetrahedral complexes are rarely observed. Reason (R): Crystal field splitting energy is less than…1 mkasked 2×
• Q18Assertion: [Co(NH 3) 5 SO 4] C l gives a white precipitate with silver nitrate solution. Reason (R): The complex…1 mk
• Q18Assertion: Chlorobenzene is resistant to nucleophilic substitution reaction at room temperature. Reason (R): C-C l bond…1 mk
• Q18Assertion: EDTA is used to determine hardness of water. Reason (R): EDTA is a bidentate ligand.1 mk
• Q18Assertion: Fe^2+ acts as a reducing agent. Reason (R): Fe^3+ state is stable due to 3 d^5 configuration.1 mk
• Q18Assertion: Trans [Cr C l 2(ox) 2]^3- shows optical isomerism. Reason (R): Optical isomerism is common in octahedral…1 mk
• Q18Assertion: Monobromination of aniline can be conveniently done by protecting the amino group by acetylation. Reason…1 mkasked 3×
• Q18Assertion: E Cu^° 2+/ Cu is positive (+0.34 V). Reason (R): Copper has high Δ a H^° and low Δ hyd H^°.1 mkasked 2×
• Q18Assertion: Zinc is not regarded as a transition element. Reason (R): In zinc, 3d orbitals are completely filled in its…1 mkasked 3×
• Q18Assertion: Nucleophilic substitution of iodoethane is easier than chloroethane. Reason (R): Bond enthalpy of C-I bond…1 mk
• Q19Show how you will synthesise: from a suitable alkene. from methanal using a suitable Grignard reagent.2 mk
• Q19An alkyl halide of molecular formula C 6 H 13 Cl on treatment with alcoholic KOH gives two isomeric alkenes and of…2 mkasked 3×
• Q19Write IUPAC names of the following: [Co(en) 2(H 2 O)(CN)]^2+ [Ni(NH 3) 6] Cl 22 mk
• Q19What is Henry's law? Give one application of it.2 mkasked 2×
• Q19What are nucleic acids? Why two strands in DNA are not identical but are complementary? 1 × 22 mk
• Q19Give the structures and IUPAC name of the products expected from the following reactions: Reaction of methanal with…2 mk
• Q19A solution is prepared by dissolving 10 g of non-volatile solute in 200 g of water. It has a vapour pressure of 31.84…2 mk
• Q19Write the structures and IUPAC names of the products expected from the following reactions: Reaction of methanal with…2 mk
• Q20Calculate Δ r G^° for the cell reaction at 25°C: Zn Zn^2+ Cd^2+ Cd Given that: OR The electrical resistance of a column…2 mk
• Q20On diluting two electrolytes'A'and'B', the Λ m of'A'increases 25 times while that of'B'increases by 1.5 times. Which of…2 mkasked 2×
• Q20The half-life of a first order reaction is 60 minutes. How long will it take to consume 90%of the reactant? [Given: log…2 mk
• Q20What happens to the rate constant k and activation energy E a as the temperature of a chemical reaction is increased?…2 mkasked 3×
• Q20The vapour pressure of pure liquid X and pure liquid Y at 25 °C are 120 mm Hg and 160 mm Hg respectively. If equal…2 mkasked 3×
• Q20Do the following conversions in not more than two steps: 2 × 1 CH 3 COOH to CH 3 COCH 3 to2 mk
• Q20Give reasons: 2 × 1 (i) Mercury cell delivers a constant potential during its life time. (ii) In the experimental…2 mkasked 3×
• Q20A chemical reaction 2 N 2 O 5( g) → 4 NO 2( g)+O 2( g) in gas phase was carried out in a closed vessel. The…2 mk
• Q20What type of deviation from Raoult's law is shown by a mixture of ethanol and acetone? Give reason. OR Define…2 mkasked 3×
• Q21Which of the following species cannot act as a ligand? Give reason. OH^-, NH 4^+, CH 3 NH 2, H 2 O The complex [Co(NH…2 mkasked 3×
• Q21How would you account for: The E^° value for the Mn^3+ / Mn^2+ couple is much more positive than that for Cr^3+ / Cr^2+…2 mk
• Q21Name the cell which: was used in Apollo Space programme. is used in automobiles and inverters. is suitable for hearing…2 mkasked 3×
• Q21The conversion of molecule A to B followed second order kinetics. If concentration of A increased to three times, how…2 mkasked 3×
• Q21Define fuel cell and write its two advantages. OR Using E^° values of X and Y given below, predict which is better for…2 mkasked 3×
• Q21Complete the following equations: 2 MnO 4^-+5 NO 2^-+6 H^+ → Cr 2 O 7^2-+14 H^++6 e^- →2 mkasked 2×
• Q22Why haloarenes are not reactive towards nucleophilic substitution reaction? Give two reasons.2 mk
• Q22The rate constant for the first order decomposition of N 2 O 5 is given by the following equation: log k=23 · 6-(2 ×…2 mkasked 3×
• Q22Write the IUPAC names of the following: 2 × 1 (i) [Co(NH 3) 5(ONO)]^2+ (ii) K 2[NiCl 4] OR (i) What is a chelate…2 mkasked 3×
• Q22Why is boiling point of o-dichlorobenzene higher than p-dichlorobenzene but melting point of para isomer is higher than…2 mk
• Q22Write equations for the following: Oxidation of chloroform by air and light Reaction of chlorobenzene with CH 3 Cl /…2 mk
• Q22What type of deviation from Raoult's law is shown by a mixture of ethanol and acetone? Give reason.2 mk
• Q22(i) How are carbohydrates stored in animal body? Mention any one organ where they are present. (ii) What is the basic…2 mkasked 3×
• Q22Write the main product formed when: n-Butyl chloride is treated with alc. KOH. 2,4,6-Trinitrochlorobenzene is subjected…2 mk
• Q23On mixing liquid X and liquid Y, volume of the resulting solution decreases. What type of deviation from Raoult's law…2 mk
• Q23Give reasons for the following: Carboxylic carbon is less electrophilic than Carbonyl carbon of aldehydes and ketones.…2 mkasked 2×
• Q23Write the mechanism of the following reaction: CH 2=CH 2+H 2 O H^+ CH 3 CH 2 OH2 mk
• Q23Write IUPAC names of the following coordination entities: [Cr(NH 3) 3(H 2 O) 3] Cl 3 K 3[Al(C 2 O 4) 3]2 mk
• Q23Write the chemical equation involved in the following reactions: 2 × 1 Reimer-Tiemann reaction Acetylation of Salicylic…2 mkasked 2×
• Q23Account for the following: (i) Phenol is a stronger acid than an alcohol. (ii) The boiling point of alcohols decreases…2 mkasked 2×
• Q23For the pair phenol and cyclohexanol, answer the following: Why is phenol more acidic than cyclohexanol? Give one…2 mkasked 3×
• Q23Predict the products of the following reactions: (i) CH 3 CH 2 OH Cu / 273 K (ii) C 6 H 5 OH Br 2(aq) OR Give reasons…2 mk
• Q23What is the difference between a nucleoside and nucleotide? 2 × 1 What products would be formed when a nucleotide from…2 mk
• Q24(i) What should be the signs (positive/negative) for E^° Cell and Δ G^° for a spontaneous redox reaction occurring…2 mkasked 3×
• Q24Which of the following is an appropriate set of reactants for the preparation of 1-methoxy-4-nitrobenzene and why?2 mk
• Q24Explain briefly: Carbylamine reaction Gabriel phthalimide synthesis2 mkasked 2×
• Q24CH 3 CH 2 CH 2 Cl+KOH ethanol 'A' HBr 'B' Identify'A'and'B'in the above reactions.2 mkasked 2×
• Q24The following data were obtained for the reaction: 2 NO 2( g)+F 2( g) → 2 NO 2 F( g) Determine the overall order of…2 mk
• Q24Write the IUPAC name for the following organic compounds: Complete the following: C 6 H 5 NO 2 Sn / HCl A Br 2 / H 2 O B2 mk
• Q24Do the following conversions in not more than two steps: 2 × 1 CH 3 CN to to = =C-CH 3 -COOH to 〈2 mk
• Q24Write the products of the following reactions: (i) (ii) OR Do the following conversions in not more than two steps: (i)…2 mkasked 3×
• Q24Write the chemical equation involved in the following: 2 × 1 Kolbe's reaction Williamson synthesis2 mk
• Q24Write the chemical equation involved in the following reactions: 2 Carbylamine reaction Gabriel phthalimide synthesis2 mkasked 3×
• Q24(i) Draw the zwitter ion structure for sulphanilic acid. (ii) How can the activating effect of -NH 2 group in aniline…2 mkasked 3×
• Q25Define denaturation of protein. What is the effect of denaturation on the structure of protein?2 mk
• Q25Write the mechanism of acid dehydration of ethanol to yield ethene.2 mk
• Q25Give the reaction of glucose with hydrogen cyanide. Presence of which group is confirmed by this reaction?2 mk
• Q25Give reasons for the following: 2 Aquatic animals are more comfortable in cold water in comparison to warm water.…2 mk
• Q25Write chemical reaction to show that open structure of D-glucose contains the straight chain. What type of linkage is…2 mkasked 2×
• Q25Give reasons: Formic acid is a stronger acid than acetic acid. Alpha ( α ) -Hydrogens of aldehydes and ketones are…2 mk
• Q25Do the following conversions in not more than two steps: 2 × 1 CH 3 CN to to2 mk
• Q25Write two differences between DNA and RNA. 1 × 22 mkasked 2×
• Q25Give the reaction of glucose with acetic anhydride. Presence of which group is confirmed by this reaction?2 mk
• Q25Write IUPAC names of the following coordination entities: [Co(NH 3) 4 Cl(NO 2)] Cl [PtCl 2(en) 2]^2+2 mk
• Q25Give the reaction of heating glucose with hydroxylamine. Presence of which group is confirmed by this reaction?2 mk
• Q26Write the mechanism of the following reaction: CH 2=CH 2+H 2 O H^+ CH 3 CH 2 OH Write the structures of the products…3 mk
• Q26For the reaction 2 N 2 O 5( g) → 4 NO 2( g)+O 2( g) at 318 K calculate the rate of reaction if rate of disappearance of…3 mkasked 3×
• Q26Write the mechanism of the following reaction: CH 3-CH 2-OH 443 K^+H^+ CH 2=CH 2+H 2 O Write the equation of the…3 mkasked 2×
• Q26Answer any 3 of the following: 3 × 1 Which isomer of C 5 H 10 gives a single monochloro compound C 5 H 9 C l in bright…3 mkasked 3×
• Q26Give reason: Measurement of osmotic pressure method is preferred for the determination of molar masses of…3 mk
• Q26(i) Write hydroboration-oxidation reaction with an example. (ii) Write the products of the following reaction: (iii)…3 mkasked 3×
• Q26(i) Write the mechanism of the following reaction: 2+1 2 CH 3 CH 2 OH [413 K]H^+ CH 3-CH 2-O-CH 2-CH 3+H 2 O (ii) Why…3 mkasked 3×
• Q26Differentiate between Ideal solution and Non-ideal solution. 30 g of urea is dissolved in 846 g of water. Calculate the…3 mkasked 2×
• Q27On the basis of crystal field theory, write the electronic configuration for d^4 with a strong field ligand for which Δ…3 mk
• Q27Complete the following reactions: 1 1/2+1 1/2=3 CH 3 CH 2 CH 2 Br [Δ] Alc. KOH HBr3 mk
• Q27Account for the following: Benzyl chloride is highly reactive towards S N 1 reaction. (±)-Butan-2-ol is optically…3 mkasked 3×
• Q27Write the structures of A, B and C in the following reactions: (i) (ii) CH 3 CH 2 Br KCN A LiAlH 4 B [0^° C]HNO 2 C OR…3 mkasked 3×
• Q27On the basis of crystal field theory write the electronic configuration for d^5 ion with a strong field ligand for…3 mk
• Q27On the basis of crystal field theory write the electronic configuration for d^5 ion with a weak ligand for which Δ 0<P.…3 mk
• Q27Write main product formed when: Methyl chloride is treated with NaI/Acetone. 2,4,6-trinitrochlorobenzene is subjected…3 mkasked 2×
• Q27When 19.5 g of F-CH 2-COOH(. Molar mass.=78 g mol^-1), is dissolved in 500 g of water, the depression in freezing point…3 mkasked 3×
• Q28How do you convert the following: (Any three) Phenol to 2-Hydroxybenzaldehyde Anisole to 2-Methoxyacetophenone Propene…3 mk
• Q28Answer any three of the following questions: Explain the type of hybridization in [Fe(CN) 6]^3- on the basis of valence…3 mkasked 3×
• Q280.3 g of acetic acid (M=60 g mol^-1) dissolved in 30 g of benzene shows a depression in freezing point equal to 0.45^°…3 mkasked 6×
• Q28A first order reaction is 50%complete in 30 minutes at 300 K and in 10 minutes at 320 K. Calculate activation energy (E…3 mkasked 3×
• Q28Illustrate Sandmeyer's reaction with an equation. Explain, why (CH 3) 2 NH is more basic than (CH 3) 3 N in aqueous…3 mkasked 3×
• Q28How do you convert the following: (Any three) Phenol to picric acid Propanone to 2-Methylpropan-2-ol Phenol to anisole…3 mkasked 2×
• Q29Give reasons for any 3 of the following observations: Penta-acetate of glucose does not react with hydroxylamine. Amino…3 mkasked 3×
• Q29The rate of a reaction doubles when temperature changes from 27°C to 37°C. Calculate energy of activation for the…3 mkasked 3×
• Q29Explain why: (i) Carboxyl group in benzoic acid is meta directing. (ii) Sodium bisulphite is used for the purification…3 mkasked 2×
• Q29Explain why: (i) Carboxyl group in benzoic acid is meta directing. (ii) Sodium bisulphite is used for the purification…3 mk
• Q29What are the hydrolysis products of (i) Lactose, (ii) Maltose?3 mk
• Q29If benzoic acid (M=122 g mol^-1) is associated into a dimer when dissolved in benzene and the osmotic pressure of a…3 mkasked 3×
• Q30Write the product when D-glucose reacts with conc. HNO 3. Amino acids show amphoteric behaviour. Why? Write one…3 mk
• Q30Draw the geometrical isomers of [Co(en) 2 Cl 2]^2+. Which geometrical isomer of [Co(en) 2 Cl 2]^2+ is not optically…3 mkasked 3×
• Q30Write the structure of product when D-Glucose reacts with the following: (any three) HI Conc. HNO 3 Br 2 water HCN3 mkasked 3×
• Q30What are the hydrolysis products of (i) Lactose, (ii) Maltose? Give the basic structural difference between starch and…3 mk
• Q30The following data were obtained during the first order thermal decomposition of C 2 H 5 Cl at a constant volume: C 2 H…3 mkasked 3×
• Q30(i) Why is the C-O bond length in phenols less than that in methanol? (ii) Arrange the following in order of increasing…3 mkasked 3×
• Q31Living systems are made up of various complex biomolecules like carbohydrates, proteins, nucleic acids, lipids, etc.…4 mkasked 3×
• Q31The carbon - oxygen double bond is polarised in aldehydes and ketones due to higher electronegativity of oxygen…4 mkasked 3×
• Q31In coordination compounds, metals show two types of linkages, primary and secondary. Primary valencies are ionisable…4 mkasked 3×
• Q31The polarity of C - X bond of alkyl halides is responsible for their nucleophilic substitution, elimination and their…4 mkasked 3×
• Q31The rate of reaction is concerned with decrease in concentration of reactants or increase in the concentration of…4 mkasked 3×
• Q31Nucleophilic Substitution Nucleophilic Substitution reaction of haloalkane can be conducted according to both S N 1 and…4 mkasked 2×
• Q32Carbohydrates are optically active polyhydroxy aldehydes and ketones. They are also called saccharides. All those…4 mkasked 3×
• Q32Coordination compounds are widely present in the minerals, plant and animal worlds and are known to play many important…4 mkasked 3×
• Q32Rahul set-up an experiment to find resistance of aqueous KCl solution for different concentrations at 298 K using a…4 mkasked 3×
• Q32Nucleophilic Substitution Nucleophilic Substitution reaction of haloalkane can be conducted according to both S N1 and…4 mk
• Q32Amines are usually formed from nitro compounds, halides, amides, imides, etc. They exhibit hydrogen bonding which…4 mkasked 3×
• Q33(i) Why is boiling point of 1 M NaCl solution more than that of 1 M glucose solution? (ii) A non-volatile solute 'X'…5 mkasked 3×
• Q33(i) Account for the following: (1) Transition metals form complex compounds. (2) The E Mn^2+ / Mn^° value for manganese…5 mkasked 3×
• Q33(i) State Kohlrausch's law of independent migration of ions. Write an expression for the limiting molar conductivity of…5 mkasked 3×
• Q33(i) Carry out the following conversions: (1) Ethanal to But-2-en-1-al (2) Propanoic acid to 2-chloropropanoic acid (ii)…5 mkasked 2×
• Q33(I) Account for the following: 3 + 2 (i) E^o value for Mn^3+ / Mn^2+ couple is much more positive than that for Cr^3+ /…5 mkasked 3×
• Q33(i) Calculate the emf of the following cell at 298 K: (ii) With the help of a graph explain why it is not possible to…5 mkasked 3×
• Q34Draw structure of the 2,4-dinitrophenylhydrazone of benzaldehyde. Which acid of the following pair is a stronger acid?…5 mkasked 3×
• Q34(i) Account for the following: (1) Zn^2+ salts are colourless while Ni^2+ salts are coloured. (2) Cr^2+ is a strong…5 mkasked 3×
• Q34(i) Write the reaction involved in Cannizaro's reaction. 1+1+3=5 (ii) Why are the boiling point of aldehydes and…5 mkasked 3×
• Q34(i) An organic compound (X) having molecular formula C 5 H 10 O can show various properties depending on its…5 mkasked 3×
• Q34(i) In 3d series, which transition element has positive E M^2+ / M value and why? (ii) Name a member of lanthanide…5 mk
• Q34(i) Carry out the following conversions: (1) Ethanal to But-2-en-1-al (2) Propanoic acid to 2-chloropropanoic acid (ii)…5 mk
• Q34(I) Give reasons: 3 + 2 (i) Aniline on nitration gives good amount of m-nitroaniline, though -NH 2 group is o/p…5 mkasked 3×
• Q34Assign reason for each of the following: (i) Manganese exhibits the highest oxidation state of+7 among the 3d series of…5 mkasked 2×
• Q35Conductivity of 2 × 10^-3 M methanoic acid is 8 × 10^-5 S cm^-1. Calculate its molar conductivity and degree of…5 mkasked 3×
• Q35A transition element X has electronic configuration [Ar] 4 s^2 3 d^3. Predict its likely oxidation states. 1+1+3=5…5 mk
• Q35Write the number of unpaired electrons in Cr^3+. (Atomic number of Cr=24 ) Complete the reaction mentioning all the…5 mk
• Q35Calculate 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: E…5 mkasked 3×
• Q35Why is chemistry of actinoids complicated as compared to lanthanoids? Complete the following reaction and justify that…5 mk