JEE Main 2023 Chemistry Question Paper Jan 24 Shift 1- Download PDF

Compound (X) undergoes the following sequence of reactions to give the lactone (Y):

What is compound X?

• (1) CH₃CH(CH₃)CHO
• (2) HOCH₂C(CH₃)₂CHO
• (3) H₂C-CH₂-CH₂-CH₂-CHO
• (4) H₂C-CH₂-CHO

Assertion (A): Hydrolysis of an alkyl chloride is a slow reaction, but in the presence of NaI, the rate of hydrolysis increases.

Reason (R): I^- is a good nucleophile as well as a good leaving group.

• (1) A is false but R is true.
• (2) A is true but R is false.
• (3) Both A and R are true, and R is the correct explanation of A.
• (4) Both A and R are true, but R is NOT the correct explanation of A.

Order of covalent bond:

A. KF > KI; LiF > KF
B. KF < KI; LiF > KF
C. SnCl₂ > SnCl₄; CuCl > NaCl
D. LiF > KF; CuCl < NaCl
E. KF < KI; CuCl > NaCl

Choose the correct combination of options

• (1) C, E only
• (2) B, C only
• (3) B, C, E only
• (4) A, B only

Increasing order of stability of the resonance structures is:[Image of resonance structures is present]

• (1) C, D, B, A
• (2) C, D, A, B
• (3) D, C, A, B
• (4) D, C, B, A

The magnetic moment of a transition metal compound has been calculated to be 3.87 B.M. The metal ion is:

• (1) Cr²⁺
• (2) Mn²⁺
• (3) V²⁺
• (4) Ti²⁺

Match List I with List II:

List I: A. Reverberatory furnace, B. Electrolytic cell, C. Blast furnace, D. Zone Refining furnace

List II: I. Pig Iron, II. Aluminum, III. Silicon, IV. Copper

• (1) A – IV, B – II, C – I, D – III
• (2) A – I, B – IV, C – II, D – III
• (3) A – I, B – III, C – II, D – IV
• (4) A – III, B – IV, C – I, D - II

It is observed that characteristic X-ray spectra of elements show regularity. When frequency to the power n, i.e., νⁿ of X-rays emitted, is plotted against atomic number Z, the following graph is obtained. What is the value of n?

• (1) 1
• (2) 2
• (3) ½
• (4) 3

Which of the phosphorus oxoacids can create a silver mirror from AgNO₃ solution?

• (1) (HPO₃)_n
• (2) H₄P₂O₅
• (3) H₄P₂O₆
• (4) H₄P₂O₇

The primary and secondary valencies of cobalt, respectively, in [Co(NH₃)₅Cl]Cl₂ are:

• (1) 3 and 5
• (2) 2 and 6
• (3) 2 and 8
• (4) 3 and 6

An ammoniacal metal salt solution gives a brilliant red precipitate on the addition of dimethylglyoxime. The metal ion is:

• (1) Cu²⁺
• (2) Co²⁺
• (3) Fe²⁺
• (4) Ni²⁺

'R' formed in the following sequence of reactions is: [Image of a reaction scheme is present]

Match List I with List II:

List I: A. Chlorophyll, B. Soda ash, C. Dentistry, Ornamental work, D. Used in white washing

List II: I. Na₂CO₃, II. CaSO₄, III. Mg²⁺, IV. Ca(OH)₂

• (1) A – III, B – I, C – II, D – IV
• (2) A – II, B – I, C – III, D – IV
• (3) A – III, B – IV, C – I, D – II
• (4) A – II, B – III, C – IV, D - I

Statement I: For colloidal particles, the values of colligative properties are of small order as compared to values shown by true solutions at the same concentration.

Statement II: For colloidal particles, the potential difference between the fixed layer and the diffused layer of same charges is called the electrokinetic potential or zeta potential.

• (1) Statement I is true but Statement II is false.
• (2) Statement I is false but Statement II is true.
• (3) Both Statement I and Statement II are true.
• (4) Both Statement I and Statement II are false.

Reaction of BeO with ammonia and hydrogen fluoride gives 'A' which on thermal decomposition gives BeF₂ and NH₄F. What is 'A'?

• (1) (NH₄)₂BeF₄
• (2) H₃NBeF₃
• (3) (NH₃)BeF₃
• (4) (NH₄)Be₂F₅

'A' and 'B' formed in the following set of reactions are:[Image of a reaction scheme is present]

In the following reaction, ‘A' is:[Image of a reaction scheme is present]

The decreasing order of the hydrogen bonding in the following forms of water is correctly represented by:

A. Liquid water, B. Ice, C. Impure water

• (1) A = B > C
• (2) B > A > C
• (3) C > B > A
• (4) A > B > C

Given below are two statements:

Statement I: Noradrenaline is a neurotransmitter.

Statement II: Low level of noradrenaline is not the cause of depression in humans.

• (1) Statement I is correct but Statement II is incorrect.
• (2) Statement I is incorrect but Statement II is correct.
• (3) Both Statement I and Statement II are correct.
• (4) Both Statement I and Statement II are incorrect.

In the depression of freezing point experiment:

A. Vapour pressure of the solution is less than that of pure solvent.
B. Vapour pressure of the solution is more than that of pure solvent.
C. Only solute molecules solidify at the freezing point.
D. Only solvent molecules solidify at the freezing point.

• (1) A and D only
• (2) B and C only
• (3) A and C only
• (4) A only

Which of the following is true about freons?

• (1) These are chlorofluorocarbon compounds.
• (2) These are chemicals causing skin cancer.
• (3) These are radicals of chlorine and chlorine monoxide.
• (4) All radicals are called freons.

Section B

Question 21:

The dissociation constant of acetic acid is x × 10^-5. When 25 mL of 0.2 M CH₃COONa solution is mixed with 25 mL of 0.02 M CH₃COOH solution, the pH of the resultant solution is found to be equal to 5. The value of x is ________

5 g of NaOH was dissolved in deionized water to prepare a 450 mL stock solution. What volume (in mL) of this solution would be required to prepare 500 mL of 0.1 M solution?

If the wavelength of the first line of the Paschen series of the hydrogen atom is 720 nm, then the wavelength of the second line of this series is _______ nm (nearest integer).

The number of correct statements from the following is _______

A. Larger the activation energy, smaller is the value of the rate constant.
B. The higher is the activation energy, higher is the value of the temperature coefficient.
C. At lower temperatures, increase in temperature causes more change in the value of k than at higher temperatures.
D. A plot of ln k vs 1/T is a straight line with slope equal to -Ea/R.

At 298 K, a 1-liter solution containing 10 mmol of Cr₂O₇^2- and 100 mmol of Cr³⁺ shows a pH of 3.0. The potential for the half-cell reaction is x × 10^-3 V. The value of x is ________

When Fe_0.93O is heated in the presence of oxygen, it converts to Fe₂O₃. The number of correct statements from the following is _______.

A. The equivalent weight of Fe_0.93O is Molecular weight / 0.79
B. The number of moles of Fe²⁺ and Fe³⁺ in 1 mole of Fe_0.93O is 0.79 and 0.14, respectively.
C. Fe_0.93O is metal deficient with a lattice comprising cubic close-packed arrangement of O^2- ions.
D. The percentage composition of Fe²⁺ and Fe³⁺ in Fe_0.93O is 85 and 15, respectively.

The d-electronic configuration of [CoCl₄]^2- in tetrahedral crystal field is e^mt_n². Sum of 'm' and the number of unpaired electrons is _______.

For independent processes at 300 K, the number of non-spontaneous processes from the following is ________

Process A: ∆H = -25 kJ mol^-1, ∆S = -80 J K^-1mol^-1
Process B: ∆H = -22 kJ mol^-1, ∆S = 40 J K^-1mol^-1
Process C: ∆H = 25 kJ mol^-1, ∆S = -50 J K^-1mol^-1
Process D: ∆H = 22 kJ mol^-1, ∆S = 20 J K^-1mol^-1

Uracil is a base present in RNA with the following structure. The percentage of nitrogen in uracil is _______.

Number of moles of AgCl formed in the following reaction is _______