JEE Main 2022 June 24 – Shift 1 Chemistry Question Paper with Solutions

SECTION – A

Multiple Choice Questions: This section contains 20 multiple choice questions. Each question has 4 choices (1), (2), (3) and (4), out of which ONLY ONE is correct.

Choose the correct answer :

1. If a rocket runs on a fuel (C₁₅H₃₀) and liquid oxygen, the weight of oxygen required and CO₂ released for every litre of fuel respectively are :

(Given : density of the fuel is 0.756 g/mL)

(A) 1188 g and 1296 g

(B) 2376 g and 2592 g

(C) 2592 g and 2376 g

(D) 3429 g and 3142 g

Answer (C)

Sol.

One litre of fuel has a mass (0.756) × 1000 g.

∴ moles of C₁₅H₃₀ =

Moles of O₂ required =

Mass of O₂ required =

Mass of CO₂ formed =

2. Consider the following pairs of electronsstrong>

(A)

(B)

(C)

The pairs of electrons present in degenerate orbitals is /are:

(A) Only (A)

(B) Only (B)

(C) Only (C)

(D) (B) and (C)

Answer (B)

Sol. For degenerate orbitals, only the value of m must be different. The value of ‘n’ and ‘l’ must be the same.

Hence, the pair of electrons with quantum numbers given in (B) are degenerate.

3. Match List-I with List-II :

Choose the most appropriate answer from the options given below.

(A) (A)-(II), (B)-(IV), (C)-(I), (D)-(III)

(B) (A)-(III), (B)-(IV), (C)-(I), (D)-(II)

(C) (A)-(III), (B)-(I), (C)-(IV), (D)-(II)

(D) (A)-(II), (B)-(I), (C)-(IV), (D)-(III)

Answer (B)

Sol.

Hence, the most appropriate answer is given in option (B)

4. For a reaction at equilibrium

the relation between dissociation constant (K), degree of dissociation (α) and equilibrium pressure (p) is given by :

(A)

(B)

(C)

(D)

Answer (B)

Sol.

∴ P (equilibrium pressure) =

Hence the correct option is (B).

5.Given below are two statements:

Statement I : Emulsion of oil in water are unstable and sometimes they separate into two layers on standing.

Statement II : For stabilisation of an emulsion, excess of electrolyte is added.

In the light of the above statements, choose the most appropriate answer from the options given below:

(A) Both Statement I and Statement II are correct

(B) Both Statement I and Statement II are incorrect.

(C) Statement I is correct but Statement II is incorrect.

(D) Statement I is incorrect but Statement II is correct.

Answer (C)

Sol. Oil in water emulsions can sometimes separate into two layers on standing.

The most relevant example for the above case is milk, which can separate into two layers on standing for a longer time. Therefore, statement (I) is correct.

On adding excess of electrolyte, coagulation occurs and emulsion is further destabilised.

Therefore, statement (II) is incorrect.

6. Given below are the oxides:

Na₂O, As₂O₃, N₂O, NO and Cl₂O₇

Number of amphoteric oxides is:

(A) 0

(B) 1

(C) 2

(D) 3

Answer (B)

Sol. Oxides

Hence, only one amphoteric oxide is present.

7. Match List-I with List -II :

Choose the most appropriate answer from the options given below:

(A) (A)-(IV), (B)-(III), (C)-(II), (D)-(I)

(B) (A)-(IV), (B)-(I), (C)-(II), (D)-(III)

(C) (A)-(II), (B)-(III), (C)-(I), (D)-(IV)

(D) (A)-(III), (B)-(IV), (C)-(II), (D)-(I)

Answer (A)

Sol.

Hence, the most appropriate option is (A).

8. The highest industrial consumption of molecular hydrogen is to produce compounds of element:

(A) Carbon

(B) Nitrogen

(C) Oxygen

(D) Chlorine

Answer (B)

Sol. Hydrogen combines with nitrogen to produce Ammonia in Haber’s process.

In this process, iron oxide is used with small amounts of K₂O and Al₂O₃ to increase the rate of attainment of equilibrium.

Optimum conditions for the production of ammonia are a pressure of 200 atm and a temperature of 700K.

Earlier, iron was used as a catalyst with molybdenum as promoter in this reaction.

9. Which of the following statements are correct?

(A) Both LiCl and MgCl₂ are soluble in ethanol.

(B) The oxides Li₂O and MgO combine with excess of oxygen to give superoxide.

(C) LiF is less soluble in water than other alkali metal fluorides.

(D) Li₂O is more soluble in water than other alkali metal oxides.

Choose the most appropriate answer from the options given below:

(A) (A) and (C) only

(B) (A), (C) and (D) only

(C) (B) and (C) only

(D) (A) and (D) only

Answer (A)

Sol. (A) Both LiCl and MgCl₂ are covalent in nature due to high polarizing power of Li⁺ and Mg⁺² ions. Hence, they are soluble in ethanol.

1. Oxides of Li₂O and MgO do not form superoxide
2. LiF is least soluble among all other alkali metal fluorides due to high lattice energy of LiF
3. Li₂O is least soluble among all other alkali metal oxides.

Hence, Statements (A) and (C) are correct.

10. Identify the correct statement for B₂H₆ from those given below:

(A) In B₂H₆, all B-H bonds are equivalent.

(B) In B₂H₆, there are four 3-centre-2-electron bonds.

(C) B₂H₆ is a Lewis acid.

(D) B₂H₆ can be synthesized from both BF₃ and NaBH₄.

(E) B₂H₆ is a planar molecule.

Choose the most appropriate answer from the options given below:

(A) (A) and (E) only

(B) (B), (C) and (E) only

(C) (C) and (D) only

(D) (C) and (E) only

Answer (C)

Sol. Structure of B₂H₆

It has two 3-centre-2-electron bonds and four
2-centre-2-electron bonds.

Hence, all B–H bonds are not equivalent.

It is an electron deficient compound as the octet of boron is incomplete.

Hence, it can behave as a Lewis acid.

It can be synthesized from both BF₃ and NaBH₄

It is a non-planar molecule.

Hence, only Statements (C) and (D) are correct.

11. The most stable trihalide of nitrogen is:

(A) NF₃

(B) NCl₃

(C) NBr₃

(D) NI₃

Answer (A)

Sol. The most stable trihalide is NF₃

Order of stability: NF₃ > NCl₃ > NBr₃ > NI₃

NCl₃ is explosive is nature.

NBr₃ and NI₃ are known only as ammoniates. The stability of trihalides decreases down the group due to weakening of N – X bond and inability of N to accommodate large sized halogen atoms (Cl, Br, I) around it.

12. Which one of the following elemental forms is not present in the enamel of the teeth?

(A) Ca²⁺

(B) P³⁺

(C) F^–

(D) P⁵⁺

Answer (B)

Sol. P⁺³ is not present is enamel of teeth.

Th compound present is [3Ca₃(PO₄)₂·CaF₂]

Which contains Ca⁺², P⁺⁵ & F^–

13. In the given reaction sequence, the major product ‘C’ is:

Answer (B)

Sol.

14. Two statements are given below:

Statement I: The melting point of monocarboxylic acid with even number of carbon atoms is higher than that of with odd number of carbon atoms acid immediately below and above it in the series.

Statement II: The solubility of monocarboxylic acids in water decreases with increase in molar mass.

Choose the most appropriate option:

(A) Both Statement I and Statement II are correct.

(B) Both Statement I and Statement II are incorrect.

(C) Statement I is correct but Statement II is incorrect.

(D) Statement I is incorrect but Statement II is correct.

Answer (A)

Sol. Statement (I) is correct as monocarboxylic acids with even number of carbon atoms show better packing efficiency in solid state, statement (II) is also correct as the solubility of carboxylic acids decreases with increase in molar mass due to increase in the hydrophobic portion with increase in the number of carbon atoms.

15. Which of the following is an example of conjugated diketone?

Answer (C)

Sol.

is a conjugated diketone.

In rest of the diketones given in the question, the two (C = O) groups are not in conjugation with each other.

16.

The major product of the above reactions is :

Answer (D)

Sol.

Hence, the correct option is (D).

17. Which of the following is an example of polyester?

(A) Butadiene-styrene copolymer

(B) Melamine polymer

(C) Neoprene

(D) Poly-β-hydroxybutyrate-co-β-hydroxy valerate

Answer (D)

Sol. Polyesters are formed by condensation reaction between alcohols and carboxylic acid.

Poly-β-hydroxybutyrate-co-β-hydroxy valerate (PHBV) is a polymer obtained by condensation reaction of 3-hydroxybutanoic acid with 3-hydroxypentanoic acid.

Hence, PHBV is a polyester.

18. A polysaccharide ‘X’ on boiling with dil. H₂SO₄ at 393 K under 2-3 atm pressure yields ‘Y’. ‘Y’ on treatment with bromine water gives gluconic acid. ‘X’ contains β-glycosidic linkages only. Compound ‘X’ is:

(A) starch

(B) cellulose

(C) amylose

(D) amylopectin

Answer (B)

Sol. Cellulose contains β-glycosidic linkages only.

Structure of cellulose

On boiling with dil. H₂SO₄ at 393 K under 2-3 atm, ‘X’ forms glucose, which given gluconic acid on treatment with bromine water.

19. Which of the following is not a broad-spectrum antibiotic?

(A) Vancomycin

(B) Ampicillin

(C) Ofloxacin

(D) Penicillin G

Answer (D)

Sol. Penicillin G is a narrow spectrum antibiotic. (Based on fact)

20. During the qualitative analysis of salt with cation y²⁺, addition of a reagent (X) to alkaline solution of the salt gives a bright red precipitate. The reagent (X) and the cation (y²⁺) present respectively are:

(A) Dimethylglyoxime and Ni²⁺

(B) Dimethylglyoxime and Co²⁺

(C) Nessler’s reagent and Hg²⁺

(D) Nessler’s reagent and Ni²⁺

Answer (A)

Sol. On addition of dimethylglyoxime to alkaline solution of Ni⁺², a bright red ppt. is obtained.

Ni⁺² +2dmg → [Ni(dmg)₂]⁺² (Bright red ppt)

SECTION – B

Numerical Value Type Questions: This section contains 10 questions. In Section B, attempt any five questions out of 10. The answer to each question is a NUMERICAL VALUE. For each question, enter the correct numerical value (in decimal notation, truncated/rounded-off to the second decimal place; e.g. 06.25, 07.00, –00.33, –00.30, 30.27, –27.30) using the mouse and the on-screen virtual numeric keypad in the place designated to enter the answer.

1. Atoms of element X form hcp lattice and those of element Y occupy

Answer (43)

Sol. Since X occupies hcp lattice,

Number of particles of type X in a unit cell = 6

Number of particles of type

∴Percentage of element

= 42.85

= 43% (approx)

2.

At 300 K, ozone is fifty percent dissociated. The standard free energy change at this temperature and 1 atm pressure is (–) ____ J mol^–1. (Nearest integer)

Answer (747)

Sol.

Given, x = 0.5

= –2.303 × 8.3 × 300 log 1.35

= –8.3 × 300 ln(1.35)

= –747 J mol^–1

3. The osmotic pressure of blood is 7.47 bar at 300 K. To inject glucose to a patient intravenously, it has to be isotonic with blood. The concentration of glucose solution in gL^–1 is _______. (Molar mass of glucose = 180 g mol^–1

R = 0.083 L bar K^–1 mol^–1) (Nearest integer)

Answer (54)

Sol. 7.47 = C × 0.083 × 300

(π = CRT)

(Where C represents the concentration of glucose solution and π represents osmotic pressure)

which in gm/L

= 54 gm/l

4. The cell potential for the following cell

Pt |H₂(g)|H⁺ (aq)|| Cu²⁺ (0.01 M)|Cu(s)

is 0.576 V at 298 K. The pH of the solution is ___ . (Nearest integer)

Answer (5)

Sol.

= 0.06 pH – 0.06

_{pH ≃ 4.93 ≃ 5}

5. The rate constants for decomposition of acetaldehyde have been measured over the temperature range 700 – 1000 K. The data has been analysed by plotting In k vs

(Given : R = 8.31 J K^–1 mol^–1)

Answer (154)

Sol.

6. The difference in oxidation state of chromium in chromate and dichromate salts is ______,

Answer (0)

Sol. Chromate ion

Dichromate ion

∴ Difference in oxidation state = zero

7. In the cobalt-carbonyl complex: [Co₂(CO)₈], number of Co-Co bonds is “X” and terminal CO ligands is “Y”. X + Y = _______.

Answer (7)

Sol. Structure of Co₂(CO)₈

Number of Co – Co bonds = 1 = X

Number of terminal CO ligands = 6 = Y

∴ X + Y = 1 + 6 = 7

8. A 0.166 g sample of an organic compound was digested with conc. H₂SO₄ and then distilled with NaOH. The ammonia gas evolved was passed through 50.0 mL of 0.5 N H₂SO₄. The used acid required 30.0 mL of 0.25 N NaOH for complete neutralisation. The mass percentage of nitrogen in the organic compound is ________.

Answer (63)

Sol. Millimoles of used acid

Millimoles of NH₃ = 30 × 0.25 = 7.5

Mass% of nitrogen

9. Number of electrophilic centres in the given compound is ______.

Answer (3)

Sol. Given compounds :

Number of electrophilic centres = 3

10. The major product ‘A’ of the following given reaction has ________ sp² hybridized carbon atoms.

2, 7-Dimethyl-2, 6-octadiene

Answer (2)

Sol.

Number of sp² hybridised carbon atoms = 2