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Chemistry questions for 2024

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1. Mass in grams of copper deposited by passing 9.6487 A current through a voltmeter containing copper sulphate solution for 100 seconds is: (Given: Molar mass of Cu = 63 g mol⁻¹, 1F = 96487 C)

$\newline$ Match List I with List II

$\newline$ Given below are two statements: $\newline$ Statement I: The boiling point of three isomeric pentanes follows the order $\newline$ n-pentane > isopentane > neopentane $\newline$ Statement II: When branching increases, the molecule attains a shape of sphere. This results in smaller surface area for contact, due to which the intermolecular forces between the spherical molecules are weak, thereby lowering the boiling point. $\newline$ $\newline$ In the light of the above statements, choose the most appropriate answer from the options given below:

4. Match List I with List II

5. Which one of the following alcohols reacts instantaneously with Lucas reagent?

6. Match List I with List II:

$\newline$ ‘Spin only’ magnetic moment is same for which of the following ions? $\newline$ $\newline$ (A) Ti³⁺ $\newline$ (B) Cr²⁺ $\newline$ (C) Mn²⁺ $\newline$ (D) Fe²⁺ $\newline$

8. On heating, some solid substances change from solid to vapour state without passing through liquid state. The technique used for the purification of such solid substances based on the above principle is known as

9. The energy of an electron in the ground state (n = 1) for He⁺ ion is -xJ, then that for an electron in n = 2 state for Be³⁺ ion in 1 J is:

10. Activation energy of any chemical reaction can be calculated if one knows the value of

11. Which plot of ln k vs 1/T is consistent with Arrhenius equation?

12.

$\newline$ Given below are two statements: $\newline$ Statement I: The boiling point of hydrides of Group 16 elements follow the order $\newline$ H₂O > H₂Te > H₂Se > H₂S. $\newline$ Statement II: On the basis of molecular mass, H₂O is expected to have a lower boiling point than the other members of the group but due to the presence of extensive H-bonding in H₂O, it has a higher boiling point. $\newline$ $\newline$

13.

The reagents with which glucose does not react to give the corresponding tests/products are $\newline$ A. Tollen’s reagent $\newline$ B. Schiff’s reagent $\newline$ C. HCN $\newline$ D. NH₂OH $\newline$ E. NaHSO₃

14. Arrange the following elements in increasing order of first ionization enthalpy: Li, Be, B, C, N Choose the correct answer from the options given below:

15. Arrange the following elements in increasing order of electronegativity: N, O, F, C, Si Choose the correct answer from the options given below:

16. The E° value for the Mn³⁺/Mn²⁺ couple is more positive than that of Cr³⁺/Cr²⁺ or Fe³⁺/Fe²⁺ due to change of

17. Match List I with List II.

18. Match List I with List II.

19. Intramolecular hydrogen bonding is present in

20.

$\newline$ Given below are two statements: $\newline$ Statement I: Aniline does not undergo Friedel-Crafts alkylation reaction. $\newline$ Statement II: Aniline cannot be prepared through Gabriel synthesis. $\newline$ $\newline$ In the light of the above statements, choose the correct answer from the options given below:

21. The highest number of helium atoms is in

22. Match List I with List II.

23. Identify the correct reagents that would bring about the following transformation:

24. The compound that will undergo Sₙ1 reaction with the fastest rate is

25. Fehling’s solution ‘A’ is

26. The most stable carbocation among the following is

27. For the reaction 2A ⇌ B + C, Kc = 4×10⁻³. At a given time, the composition of reaction mixture is: [A] = [B] = [C] = 2×10⁻³ M. Then, which of the following is correct?

28.

The Henry’s law constant $(K_H)$ values of three gases (A, B, C) in water are 145, 2×10⁻⁵ and 35 kbar, respectively. The solubility of these gases in water follow the order:

29. A compound with a molecular formula of C₆H₁₄ has two tertiary carbons. Its IUPAC name is:

30. In which of the following equilibria, Kp and Kc are NOT equal?

31. Which reaction is NOT a redox reaction?

32.

$\newline$ Given below are two statements: $\newline$ Statement I: Both [Co(NH₃)₆]³⁺ and [CoF₆]³⁻ complexes are octahedral but differ in their magnetic behavior. $\newline$ Statement II: [Co(NH₃)₆]³⁺ is diamagnetic whereas [CoF₆]³⁻ is paramagnetic. $\newline$ $\newline$ In the light of the above statements, choose the correct answer from the options given below:

33. 1 gram of sodium hydroxide was treated with 25 mL of 0.75 M HCl solution, the mass of sodium hydroxide left unreacted is equal to

34. Among Group 16 elements, which one does NOT show -2 oxidation state?

35.

Which of the following processes entropy increases? $\newline$ A. A liquid evaporates to vapour. $\newline$ B. Temperature of a crystalline solid lowered from 130 K to 0 K. $\newline$ C. $2$ NaHCO $_3(s) \rightarrow$

36. Match List I with List II. List I (Conversion) A. 1 mol of H₂O to O₂ B. 1 mol of MnO₄⁻ to Mn²⁺ C. 1.5 mol of Ca from molten CaCl₂ D. 1 mol of Fe₂O₃ to Fe List II (Number of Faraday required) I. 3F II. 2F III. 1F IV. 5F Choose the correct answer from the options given below:

37. Major products A and B formed in the following reaction sequence are:

38. Consider the following reaction in a sealed vessel at equilibrium with concentrations of: N₂ = 3.0 × 10⁻³ M, O₂ = 4.2 × 10⁻³ M, and NO = 2.8 × 10⁻³ M 2NO(g) ⇌ N₂(g) + O₂(g) If 0.1 mol L⁻¹ of NO(g) is taken in a closed vessel, what will be the degree of dissociation (α) of NO(g) at equilibrium?

39.

The products A and B obtained in the following reactions, respectively, are: $\newline {3ROH + PCl₃ → 3RCl + A} \newline {ROH + PCl₅ → RCl + HCl + B}$

40.

$\newline$ Using inorganic qualitative analysis, arrange the given increasing group number from O to VI: $\newline$ A. Al³⁺ $\newline$ B. Cu²⁺ $\newline$ C. Ba²⁺ $\newline$ D. Co²⁺ $\newline$ E. Mg²⁺ $\newline$

41. During the preparation of Mohr’s salt solution (Ferrous ammonium sulphate), which of the following acid is added to prevent hydrolysis of Fe²⁺ ion?

42. The work done during reversible isothermal expansion of one mole of hydrogen gas at 25°C from pressure of 20 atmosphere to 10 atmosphere is: (Given R = 2.0 cal K⁻¹ mol⁻¹)

43. For the given reaction: C ≡ C-H + KMnO₄/H⁺ → ‘P’ (major product) What is ‘P’?

44. The plot of osmotic pressure (π) vs concentration (mol L⁻¹) for a solution gives a straight line with slope 25.73 L bar mol⁻¹. The temperature at which the osmotic pressure measurement is done is: (Use R = 0.083 L bar mol⁻¹ K⁻¹)

45.

Identify the major product C formed in the following reaction sequence: $\newline CH₃-CH₂-CH₂-I \xrightarrow{NaCN} A \xrightarrow[partial hydrolysis]{OH⁻} B \xrightarrow[Br₂]{NaOH} C \ (major)$

46. A compound X contains 32% of A, 20% of B and remaining percentage of C. Then, the empirical formula of X is: (Given atomic masses of A=64; B=40; C=32 u)

47. The rate of a reaction quadruples when temperature changes from 27°C to 57°C. Calculate the energy of activation. (Given R = 8.314 J K⁻¹ mol⁻¹, log 4 = 0.6021)

48. Identify the correct answer:

49. The pair of lanthanoid ions which are diamagnetic is

50.

$\newline$ Given below are two statements: $\newline$ $\newline$ Statement I: [Co(NH₃)₆]³⁺ is a homoleptic complex whereas [Co(NH₃)₄Cl₂]⁺ is a heteroleptic complex. $\newline$ $\newline$ Statement II: Complex [Co(NH₃)₆]³⁺ has only one kind of ligand but [Co(NH₃)₄Cl₂]⁺ has more than one kind of ligands. $\newline$ $\newline$