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1. Enzymes mediate biochemical reactions inside the cells by

2. Oxime is formed when propanone reacts with

3. All of the following polymers are formed by the elimination of a small molecule as a byproduct EXCEPT

4. The given diagram depicts a type of inhibition in an enzyme-catalysed reaction.

The inhibitor in this reaction is classified as non-competitive because it

5. The oxidising agent that can convert a primary alcohol into a carboxylic acid is

6. The CORRECT order of reactivity of alcohol with reference to O‒H bond cleavage is

7. Polyvinyl chloride (PVC) is an example of

8. Which of the following alcohols will be LEAST soluble in water?

9. Which of the following nitrogenous bases is absent in ribonucleic acid (RNA)?

10. An alcohol that reacts with concentrated HCl in anhydrous ZnCl2 and forms an oily layer immediately is

11. Which of the following is the MOST stable and MAJOR product of this reaction?

12. A positive result is obtained when the haloform test is carried out on

13. If C₆H₅CHO reacts with KMnO₄, then the product of this reaction would be

14. The minimum number of carbon atoms required to show chain isomerism in aldehyde is

15. The weakest hydrohalic acid is

16. Which of the following carbocation is the MOST stable in polar solvents?

17. The given diagram shows the interconversion of carboxylic acid derivatives represented as P, Q, R and S.

The option that CORRECTLY depicts P, Q, R and S is

18. The CORRECT sequence of events in an electrophilic substitution reaction of benzene is

  1. elimination of a proton
  2. generation of a catalyst
  3. formation of an arenium ion
  4. generation of an electrophile

19. In the given reaction, X is identified as

20. Consider the given fission reactions.

The reaction(s) that represent(s) heterolytic fission is/ are

21. Formic acid and ethanol both have nearly identical molecular weights, but formic acid has the highest boiling point. This is because formic acid

22. The oxide of an element X has a giant structure while its chloride can readily be hydrolysed.

Based on the given information, the element X is

23. Which of these compounds reacts immediately with Lucas reagent and forms an oily layer by
turning the solution turbid?

24. In a molecule of ethyne, the total numbers of sigma (σ) and pi (π) bonds are

25. Which of the following chlorides of period 3 elements is an ionic compound?

26. The product X formed in the given chemical reaction is

27. All of the following are the significances of dyes EXCEPT that they are used in

28. Consider the given reaction in aqueous medium.

10FeSO₄ + 2KMnO₄ + 8H₂SO₄ → 5Fe₂(SO₄)₃ + 2MnSO₄ + K₂SO₄ + 8H₂O

In the given reaction, the purple colour of potassium permanganate fades away gradually
because the

29. Which of the following is TRUE about diethyl ether molecule?

30. Boiling points of consecutive alcohols in the homologous series generally increase with the

31. A class of dyes has the following features.

  • It has no natural affinity towards fabric.
  • It is applied to fabric with the help of salts.
  • It forms an insoluble coordinate complex between the dye and the fabric.

These dyes are MOST suitable for

32. The total number of sigma bonds in a benzene molecule is

33. Pyridine is a basic, heterocyclic amine. Its structure is represented as

34. The option that CORRECTLY depicts the number of π-bonds and the shape of ethene molecule is

35. Which of the following steps in water purification removes H2S gas and volatile organic compounds?

36. Given are the different types of alkyl halides on the basis of ‘R’ groups.

  1. RCH₂-X
  2. R₂CH-X
  3. R₃C-X
  4. CH₃-X

The increasing order of reactivity of these alkyl halides for the SN2 reaction mechanism is

37. Given is the reaction of n-propyl benzene with alkaline KMnO4 followed by acidic hydrolysis.

The MAIN product obtained at the completion of this reaction will be

38. Which of the following acts as a meta-directing group in the electrophilic substitution reaction of benzene?

39. In forming coordination complexes, all of the following species would act as a ligand EXCEPT

40. The compound that has an optical isomer is

41. The compound that contains more than one chiral centre is

42. Consider the following reaction.

The products X and Y in the given reaction are

43. In contrast to alcohols, phenols are

44. The condition required to extract aliphatic and aromatic components from coal is

45. An example of the simplest arene is

46. Given is the structure of resorcinol.

The International Union of Pure and Applied Chemistry (IUPAC) name of this compound is

47. The product Z in the given chemical reaction is

48. Dissolution of methane gas in water releases enough amount of energy that can overcome

  1. Van der Waals dispersion forces in methane molecules
  2. carbon-hydrogen bonding in methane molecules
  3. hydrogen bonding in water molecules

49. The group that replaces a hydrogen atom in the Friedal-Crafts acylation of benzene is

(Note: X in the given structures represents Br or Cl.)

50. The oxidative cleavage of 1,2-diol by periodic acid (HIO4) gives two carbonyl compounds. The reaction occurs via the formation of a cyclic periodate ester.

The structure of cyclic periodate intermediate formed in the given reaction would be

Your score is

2024
/50

Paper I 2024

1. The decomposition products of PbCl₄ at room temperature are

2. The weakest hydrohalic acid is

3. The oxide of period 3 that will produce an acidic solution in an aqueous medium is

4. The first ionisation energy generally decreases down the group in the periodic table because there is an increase in

  1. atomic radius
  2. nuclear charge
  3. electron affinity
  4. number of screening electrons

5. All of the following trends are observed in period 3 elements when moving from left to right in the periodic table EXCEPT a gradual

6. If the coordination sphere carries a negative charge, then the suffix for transition metal ion in International Union of Pure and Applied Chemistry (IUPAC) nomenclature would be

7. Cu²⁺ ion is more stable than Cu⁺ ion in an aqueous solution because Cu²⁺ ion has

(Note: ⁶²-⁵₂₉Cu)

8. In forming coordination complexes, all of the following species would act as a ligand EXCEPT

9. The electronic structure of iron(II) ion is

(Note: ⁵⁶₂₆Fe)

10. The compound which is alicyclic in nature is

11. All of the following amino acid molecules exhibit stereoisomerism EXCEPT

12. The compound that contains a carbonyl group is

13. In the nitration of benzene, the reaction between nitric acid and sulphuric acid generates an electrophile that is

14. The reaction of Cl2 with toluene in dark, in the presence of a catalyst (FeCl3) and at low temperatures yields

15. Consider the following structural features of a class of compounds.

  • Each carbon is sp³ hybridised.
  • Complete rotation is restricted around the single bond.
  • Constitutional isomers are possible.
  • The most stable form contains six carbon atoms.

The class of compounds that exhibits these features is

16. In a molecule of ethyne, the total numbers of sigma (σ) and pi (π) bonds are

17. The compound which can be used as an alternate to chlorofluorocarbons in refrigeration is

18. Smog is a combination of smoke and fog.

Smog is chemically reducing in nature if it contains a high concentration of

19. One of the parameters to check water purity is electrical conductivity which measures the amount of

20. The application of green chemistry in the industrial sector does NOT help to

21. All of the following are true about SN2 reactions EXCEPT that they

22. The polar nature of the N–H bond in amines results in

23. Pyridine is a basic, heterocyclic amine. Its structure is represented as

24. When butyl magnesium bromide reacts with carbon dioxide gas, it forms

25. The carboxylic acid derivative which is the LEAST reactive is

26. The structure of organic compound which is prepared by replacing the active hydrogen of CH₃COOH with an alkyl group is

27. The given chemical reaction shows oxidation of methanol in two steps.

The resultant X and Y in these steps are

28. The molecules of formic acid exist as dimers in vapour phase due to

29. Given is the structure of resorcinol.

The International Union of Pure and Applied Chemistry (IUPAC) name of this compound is

30. Which of these compounds reacts immediately with Lucas reagent and forms an oily layer by
turning the solution turbid?

31. Diazonium salt is formed as an intermediate during the preparation of phenol from

32. Which of the following sets of substances produces an ether through Williamson synthesis reaction?

33. In cold state, H3C – H2C – O – CH2 – CH3 is unable to react with sodium metal because of the absence of

34. Which of the following ketones will have the LOWEST boiling point?

35. The product(s) of the given reaction is/ are

36. An organic compound X undergoes two different reactions: oxidation and reduction and the results are as follows.

Based on these results, the structure of X is identified as

37. Consider the following characteristics.

  1. It is non-reducing.
  2. It is a disaccharide.
  3. It gives a positive result with Fehling’s test.
  4. It gives a positive result with Benedict’s test.

The characteristics that represent fructose as a ketonic sugar are

38. A disproportionation reaction between two benzaldehyde molecules in the presence of sodium hydroxide base results in the formation of sodium benzoate and benzyl alcohol.

The chemical reaction described in the given statement is an example of

39. In contrast to ribonucleic acid (RNA), deoxyribonucleic acid (DNA) strands

40. The chemical which is released by the pancreatic glands after having a meal is

41. The given diagram depicts a type of inhibition in an enzyme-catalysed reaction.

The inhibitor in this reaction is classified as non-competitive because it

42. The characteristic feature of the primary structure of a protein molecule is the

43. he following are the significances of dyes EXCEPT that they are used in

44. Polyvinyl chloride (PVC) is used in the making of

45. Consider the given characteristics of a class of organic compounds.

  • Elastic in nature
  • Derivatives of petrochemicals
  • Made of monomers and polymers

Based on these characteristics, the class of compounds is identified as

46. The pair that matches the component of paint with its appropriate purpose is

47. Which of the following monomers does NOT undergo free radical polymerisation to form thermoplastics?

48. The CORRECT sequence of the five stages in the working of a mass spectrometer is

49. The molecule that will absorb in the ultraviolet-visible region of electromagnetic spectrum is

50. Consider the given graph of an atomic emission spectroscopy.

Based on the spectrum, the variables on x and y axes are

Your score is

2023
/50

Paper I 2023

1. The halogen that CANNOT oxidise other halide ions is

2. Based on the presence of vacant d-orbital in chlorine atom, it shows all of the following oxidation states EXCEPT

3. An atom of caesium loses an electron more readily than an atom of lithium although they both belong to group IA. This is because caesium possesses

4. The oxide of an element X has a giant structure while its chloride can readily be hydrolysed.

Based on the given information, the element X is

5. Which of the following chlorides of period 3 elements is an ionic compound?

6. The d-block element that shows the HIGHEST value of oxidation number in forming complex compounds is

7. A compound of platinum has coordination number 6 and contains one cation and two chloride ions. This compound is formed as result of a combination of platinum(IV) chloride with ammonia.

Based on this information, the formula of this compound is

8. All of the following are characteristics of an alloy EXCEPT that it

9. In transition metal complex, the electromagnetic region that corresponds to the energy of d-d transition of electrons is

10. In the given structure, the carbon which makes this compound optically active is labelled as

11. The compound that contains more than one chiral centre is

12. In the given structure of glutamine amino acid, the encircled functional group is

13. In the given reaction aluminium chloride acts as a/an

14. Which of the following is the MOST stable and MAJOR product of this reaction?

15. The total number of sigma bonds in a benzene molecule is

16. Which of the following substituents on benzene ring will make it LEAST reactive in electrophilic substitution reactions?

17. Which of the following steps in water purification removes H2S gas and volatile organic compounds?

18. Volatile organic compounds enter the atmosphere through

19. If the atmosphere contains excessive quantity of CO2, then its impact on greenhouse effect and Earth’s temperature would be

20. The acid that has the LEAST harmful effect on animals and plants is

21. Which of the following carbocation is the MOST stable in polar solvents?

22. The CORRECT decreasing order of reactivity of alkyl halides is

23. Which reagent is involved in preparing 2-methylpropanenitrile from 2-iodopropane?

24. When an amide reacts with lithium tetrahydridoaluminate (LiAlH4) in dry ether (C2H5OC2H5) at room temperature, it forms an amine.

In comparison to the amide used, the prepared amine will have

25. Which of the following options is FALSE with reference to the presence of carboxylic acids in different natural products?

26. If phenyl or vinyl group is attached to a carboxylic acid, it changes its inductive effect and acidity.

The option that shows this change in inductive effect and acidity due to the presence of these groups is

27. The compounds X, Y and Z are

28. The reaction between X and Y is catalysed by

29. An alcohol that reacts with concentrated HCl in anhydrous ZnCl2 and forms an oily layer immediately is

30. In cold state, H3C – H2C – O – CH2 – CH3 does not react with sodium metal because of the absence of all of the following EXCEPT

31. The physical characteristic that is INCORRECT for ethanol is that it

32. Which of the following alcohols will be LEAST soluble in water?

33. A positive result is obtained when the haloform test is carried out on

34. If C₆H₅CHO reacts with KMnO₄, then the product of this reaction would be

35. The name given to this ketone by the International Union of Applied and Pure Chemistry (IUPAC) is

36. Oxime is formed when propanone reacts with

37. Sonia has to prepare a 1° alcohol from a carboxylic acid by using hydride reagents via aldehyde formation.

Which of the following reducing agent would be her BEST choice to perform the given reaction?

38. In the given equation, the resultant Z would be

39. Which of the following nitrogenous bases is absent in ribonucleic acid (RNA)?

40. Compounds that are formed by combining glycerol with three molecules of fatty acids are called

41. The spiral coiling of polypeptide chains in a protein molecule represent its

42. Enzymes mediate biochemical reactions inside the cells by

43. The characteristic(s) of thermoplastic synthetic adhesives is/ are

  1. durability
  2. heat resistance
  3. modification without degradation

44. Cracking is described as a process in which

45. Nylon-6,6 is a polymer which is formed by the combination of

  1. adipic acid
  2. vinyl chloride
  3. hexamethylene diammine

46. A home garden can be protected from aphids, ants, beetles and other pests in an eco-friendly, low cost and organic way.

All of the following aerosols can be used for the given purpose EXCEPT

47. All of the following are examples of synthetic polymers EXCEPT

48. In atomic absorption spectroscopy, the type(s) of transition involved is/are

  1. electronic
  2. vibrational
  3. rotational

49. The band that infers the C=O stretching vibrations in the given IR spectrum of acetone is

50. A scientist burns an organic compound through combustion analysis to determine the percentage of carbon, hydrogen and oxygen present in it.

The products he/ she will obtain during combustion analysis are

Your score is

2022
/50

Paper I 2022

1. The decomposition products of PbCl4 at room temperature are

2. The CORRECT order of electrical conductivity in the elements of 3rd period is

3. The complete reaction of chlorine with water in the presence of bright sunlight is written as

4. A non-metal is MOST reactive when it has a

5. . The systematic name of the transition metal complex [Co(NO₂)₃(NH₃)₃] is

6. The shape of a coordination complex with coordination number 4 would be

7. The deep purple colour of KMnO₄ is due to

8. The description that is CORRECT about monodentate ligand is that it always

9. Which of the following amino acids is optically inactive?

10. How many stereoisomers can exist for a compound with 3 chiral centres?

11. Closed chain hydrocarbons that are non-benzenoid and follow the general formula of CnH2n are classified as

12. Which of the following organic compounds contains TWO chiral centres?

13. Which option represents functional group isomers?

14. CH₃COOC₃H₇ is the structural formula of

15. Organic compounds X and Y have same molecular formula that is C₃H₆O.

Based on the given statement, the type of isomerism that differentiates X from Y is

16. Iso-pentane and neo-pentane are isomers that show a difference in

17. The product obtained by the chlorination of nitrobenzene is

18. Based on the structures of molecules, which of the following p-systems is a conjugated system?

19. The CORRECT sequence of events in an electrophilic substitution reaction of benzene is

  1. elimination of a proton
  2. generation of a catalyst
  3. formation of an arenium ion
  4. generation of an electrophile

20. Consider the given fission reactions.

The reaction(s) that represent(s) heterolytic fission is/ are

21. The option that CORRECTLY depicts the number of π-bonds and the shape of ethene molecule is

22. Dissolution of methane gas in water releases enough amount of energy that can overcome

  1. Van der Waals dispersion forces in methane molecules
  2. carbon-hydrogen bonding in methane molecules
  3. hydrogen bonding in water molecules

23. Benzene shows greater stability as compared to the corresponding alkene because of its

24. The group that replaces a hydrogen atom in the Friedal-Crafts acylation of benzene is

(Note: X in the given structures represents Br or Cl.)

25. The elimination reaction is favoured over substitution reaction when there is crowding within the substrate molecule. This is because, from tertiary planar carbonium ion, the removal of

26. Which of the following carbon halide bonds is the STRONGEST?

27. Grignard’s reagents (RMgX) can convert

28. The given compound undergoes SN1 reaction mechanism when it is treated with CH3OH which
is a weak nucleophile and a solvent.

Based on this information, the MAJOR product expected from this reaction will be

29. Boiling points of consecutive alcohols in the homologous series generally increase with the

30. The CORRECT order of reactivity of alcohol with reference to O‒H bond cleavage is

31. When Lucas reagent reacts with an alcohol, ZnCl₂ acts as a

32. The oxidative cleavage of the given diol produces

33. Consider the given structure of an aromatic ether.

When this ether is treated with the excess of anhydrous hydrogen iodide, the products formed will be

34. A reversible reaction occurs when propanol is treated with ethanoic acid under the following reaction conditions.

  1. Presence of concentrated sulphuric acid
  2. Reflux at 180°C

The MAJOR product of this reaction will be

35. In humans, long-term exposure to formalin can cause

36. The product X formed in the given chemical reaction is

37. When the given compound is heated in the presence of a dilute acid, it forms an unsaturated carbonyl compound Y.

Based on the given information, the structure of compound Y will be

38. Consider the given general reaction of a carbonyl compound

The given base catalysed reaction represents

39. Which class of alcohol is produced when an aldehyde or a ketone is hydrolysed after reaction with LiAlH₄?

40. In the given reaction, X is identified as

41. The product Y in the given reaction would be

42. The oxidising agent that can convert a primary alcohol into a carboxylic acid is

43. All of the following conversion reactions of carboxylic acid derivatives are possible EXCEPT

44. Formic acid and ethanol both have nearly identical molecular weights, but formic acid has the highest boiling point. This is because formic acid

45. All of the following naturally occurring carboxylic acids are used in soap making EXCEPT

46. The MAJOR product of the given reaction is

47. All of the following are the significances of dyes EXCEPT that they are used in

48. Which of the following processes exemplifies the formation of macromolecules from small organic molecules?

49. All of the following polymers are formed by the elimination of a small molecule as a byproduct EXCEPT

50. Polyvinyl chloride (PVC) is an example of

Your score is

2021
/50

Paper I 2021

1. Hydrofluoric acid (HF) is classified as the weakest acid because it possesses

2. Consider the following properties.

  1. Low electronegativity
  2. High ionisation enthalpy
  3. Small atomic and ionic size

Amongst group IIA elements, beryllium shows anomalous behaviour MAINLY due to

3. An element ‘indium’ belongs to group IIIA and period 5 of the modern periodic table.
The electronic configuration for the given element is

4. Thermodynamically, the MOST stable oxidation state of carbon is

5. Elements which often show variable oxidation states and form coloured compounds are called

6. If the coordination sphere carries a negative charge, then the suffix for transition metal ion in International Union of Pure and Applied Chemistry (IUPAC) nomenclature would be

7. Consider the given reaction in aqueous medium.

10FeSO₄ + 2KMnO₄ + 8H₂SO₄ → 5Fe₂(SO₄)₃ + 2MnSO₄ + K₂SO₄ + 8H₂O

In the given reaction, the purple colour of potassium permanganate fades away gradually
because the

8. Consider the following structural arrangements of ligands around the central ion.

The structures that have the coordination number 4 are

9. The condition required to extract aliphatic and aromatic components from coal is

10. Consider the given structure of four-carbon sugar.

How many chiral centres are present in this structure?

11. The compound that has an optical isomer is

12. Given molecules are the isomers of each other.

The type of isomerism these molecules exemplify is

13. Given is one of the positional isomers of aliphatic amine.

CH₃ – CH₂ – CH₂ – CH₂ – CH₂ – NH₂

The number of possible positional isomers for this amine is

(Note: The count should not include the given structure.)

 

14. The residue left behind after destructive distillation of coal is

15. The minimum number of carbon atoms required to show chain isomerism in aldehyde is

16. An example of the simplest arene is

17. Consider the following structural features of a class of compounds.

  • Each carbon is sp3 hybridised
  • Complete rotation is restricted around the single bond.
  • Constitutional isomers are possible.
  • The most stable form contains six carbon atoms.

The class of compounds that exhibits these features is

18. A common reaction for both the molecules of ethene and benzene is

19. The given equation shows a reaction of ethyne with the sodium metal.

In this reaction, the acidity of ethyne is due to a

20. When ultraviolet radiations are passed through a gaseous mixture of bromine and ethane, it forms bromoethane by following the mechanism of

21. Consider the following reaction.

The products X and Y in the given reaction are

22. Which of the following acts as a meta-directing group in the electrophilic substitution reaction of benzene?

23. The reagent(s) required for the given chemical reaction is/ are

24. The CORRECT number of sigma bonds in the given organic compound is

25. The product Z in the given chemical reaction is

26. Consider the given alkyl halide.

If the given alkyl halide is heated with alcoholic potassium hydroxide, then the favoured mechanism of reaction will be

27. Given are the two ways through which a secondary carbocation can react in a polar solvent.

In the given scheme, X and Y act as

28. Given are the different types of alkyl halides on the basis of ‘R’ groups.

  1. RCH₂-X
  2. R₂CH-X
  3. R₃C-X
  4. CH₃-X

The increasing order of reactivity of these alkyl halides for the SN2 reaction mechanism is

29. Which of the following is TRUE about diethyl ether molecule?

30. The addition of LiAlH4 to ethanal followed by hydrolysis yields

31. The oxidative cleavage of 1,2-diol by periodic acid (HIO4) gives two carbonyl compounds. The reaction occurs via the formation of a cyclic periodate ester.

The structure of cyclic periodate intermediate formed in the given reaction would be

32. Given is the structure of resorcinol.

The International Union of Pure and Applied Chemistry (IUPAC) name of this compound is

33. Which of the following exemplifies the use of alcohol as a disinfectant?

34. In contrast to alcohols, phenols are

35. Consider the given reaction of ketone.

The given reduction reaction of ketone is identified as

36. Consider the given closed ring structures of two different carbohydrates.

The functional group(s) that structures I and II contain(s) in their open chain structures is/ are

37. Given is the nucleophilic addition reaction of propanone.

The nucleophile that attacks the carbonyl carbon in this reaction is the

38. A colourless, strong smelling gas that contains a carbonyl group and is used in making pressed-wood products as well as a preservative of biological specimen is

39. The major product that is obtained when one mole ethanal reacts reversibly with two moles of ethanol in the presence of dry hydrogen chloride gas is

40. Given is the general structure of a carbonyl compound.

The carbonyl compound only shows iodoform reaction when R1 and R2 are

41. The given diagram shows the interconversion of carboxylic acid derivatives represented as P, Q, R and S.

The option that CORRECTLY depicts P, Q, R and S is

42. Given is the reaction of n-propyl benzene with alkaline KMnO4 followed by acidic hydrolysis.

The MAIN product obtained at the completion of this reaction will be

43. Which of the following CORRECTLY represents X and Y in the given equation?

CH₃C≡N+ 2H₂O + HCl (excess) → X + Y

44. The structure that represents the dimer of carboxylic acid is

45. Two moles of Grignard’s reagent are used to convert an ester into a tertiary alcohol.

If one mole of Grignard’s reagent is added, then the product formed is a/an

46. Which of the following compounds is the MOST acidic?

47. The dye that was prepared for the first time on fabric by the reaction of diazotised p-nitroaniline with β-naphthol was

48. Which of the following fractions of petroleum is used to obtain petrol?

49. The given equation shows a petrochemical and its derivative.

Which of the following pairs of monomers and polymers is shown in the given polymerisation
process?

50. A class of dyes has the following features.

  • It has no natural affinity towards fabric.
  • It is applied to fabric with the help of salts.
  • It forms an insoluble coordinate complex between the dye and the fabric.

These dyes are MOST suitable for

Your score is

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