JEE MAIN - Chemistry (2024 - 5th April Morning Shift)

1

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A) : Cis form of alkene is found to be more polar than the trans form.

Reason (R) : Dipole moment of trans isomer of 2-butene is zero.

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

Answer
(C)
Both $$(\mathbf{A})$$ and $$(\mathbf{R})$$ are true and $$(\mathbf{R})$$ is the correct explanation of $$(\mathbf{A})$$
2

Given below are two statement :

Statements I : Bromination of phenol in solvent with low polarity such as $$\mathrm{CHCl}_3$$ or $$\mathrm{CS}_2$$ requires Lewis acid catalyst.

Statements II : The Lewis acid catalyst polarises the bromine to generate $$\mathrm{Br}^{+}$$.

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

Answer
(C)
Statement I is false but Statement II is true
3

The incorrect postulates of the Dalton's atomic theory are :

(A) Atoms of different elements differ in mass.

(B) Matter consists of divisible atoms.

(C) Compounds are formed when atoms of different element combine in a fixed ratio.

(D) All the atoms of given element have different properties including mass.

(E) Chemical reactions involve reorganisation of atoms.

Choose the correct answer from the options given below :

Answer
(A)
(B), (D) only
4

Given below are two statements :

Statement I : Nitration of benzene involves the following step -

JEE Main 2024 (Online) 5th April Morning Shift Chemistry - Hydrocarbons Question 17 English

Statement II : Use of Lewis base promotes the electrophilic substitution of benzene.

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

Answer
(B)
Statement I is correct but Statement II is incorrect
5
Which of the following gives a positive test with ninhydrin ?
Answer
(C)
Egg albumin
6

Given below are two statements: One is labelled as Assertion (A) and the other is labelled as Reason (R)

Assertion (A) : Enthalpy of neutralisation of strong monobasic acid with strong monoacidic base is always $$-57 \mathrm{~kJ} \mathrm{~mol}^{-1}$$

Reason (R) : Enthalpy of neutralisation is the amount of heat liberated when one mole of $$\mathrm{H}^{+}$$ ions furnished by acid combine with one mole of $${ }^{-} \mathrm{OH}$$ ions furnished by base to form one mole of water.

In the light of the above statements, choose the correct answer from the options given below.

Answer
(B)
Both (A) and (R) are true and (R) is the correct explanation of (A)
7

Given below are two statements:

Statement I: In group 13, the stability of +1 oxidation state increases down the group.

Statement II : The atomic size of gallium is greater than that of aluminium.

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

Answer
(B)
Statement I is correct but Statement II is incorrect
8
The metal that shows highest and maximum number of oxidation state is :
Answer
(B)
Mn
9
Number of $$\sigma$$ and $$\pi$$ bonds present in ethylene molecule is respectively :
Answer
(B)
5 and 1
10
An organic compound has $$42.1 \%$$ carbon, $$6.4 \%$$ hydrogen and remainder is oxygen. If its molecular weight is 342 , then its molecular formula is :
Answer
(B)
$$\mathrm{C}_{12} \mathrm{H}_{22} \mathrm{O}_{11}$$
11

For the Compounds :

(A) $$\mathrm{H}_3 \mathrm{C}-\mathrm{CH}_2-\mathrm{O}-\mathrm{CH}_2-\mathrm{CH}_2-\mathrm{CH}_3$$

(B) $$\mathrm{H}_3 \mathrm{C}-\mathrm{CH}_2-\mathrm{CH}_2-\mathrm{CH}_2-\mathrm{CH}_3$$

(C) JEE Main 2024 (Online) 5th April Morning Shift Chemistry - Alcohols, Phenols and Ethers Question 11 English 1

(D) JEE Main 2024 (Online) 5th April Morning Shift Chemistry - Alcohols, Phenols and Ethers Question 11 English 2

The increasing order of boiling point is :

Choose the correct answer from the options given below :

Answer
(B)
$$ (\mathrm{B})<(\mathrm{A})<(\mathrm{C})<(\mathrm{D}) $$
12
The correct order of ligands arranged in increasing field strength.
Answer
(C)
$$\mathrm{Br}^{-}<\mathrm{F}^{-}<\mathrm{H}_2 \mathrm{O}<\mathrm{NH}_3$$
13
The number of neutrons present in the more abundant isotope of boron is '$$x$$'. Amorphous boron upon heating with air forms a product, in which the oxidation state of boron is '$$y$$'. The value of $$x+y$$ is _________ .
Answer
(A)
9
14
Which one of the following complexes will exhibit the least paramagnetic behaviour ? [Atomic number, $$\mathrm{Cr}=24, \mathrm{Mn}=25, \mathrm{Fe}=26, \mathrm{Co}=27$$]
Answer
(C)
$$\left[\mathrm{Co}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+}$$
15
Molar ionic conductivities of divalent cation and anion are $$57 \mathrm{~S~cm}^2 \mathrm{~mol}^{-1}$$ and $$73 \mathrm{~S~cm}^2 \mathrm{~mol}^{-1}$$ respectively. The molar conductivity of solution of an electrolyte with the above cation and anion will be:
Answer
(D)
$$130 \mathrm{~S} \mathrm{~cm}^2 \mathrm{~mol}^{-1}$$
16

Identify 'A' in the following reaction :

JEE Main 2024 (Online) 5th April Morning Shift Chemistry - Aldehydes, Ketones and Carboxylic Acids Question 21 English

Answer
(D)
JEE Main 2024 (Online) 5th April Morning Shift Chemistry - Aldehydes, Ketones and Carboxylic Acids Question 21 English Option 4
17

The statement(s) that are correct about the species $$\mathrm{O}^{2-}, \mathrm{F}^{-}, \mathrm{Na}^{+}$$ and $$\mathrm{Mg}^{2+}$$.

(A) All are isoelectronic

(B) All have the same nuclear charge

(C) $$\mathrm{O}^{2-}$$ has the largest ionic radii

(D) $$\mathrm{Mg}^{2+}$$ has the smallest ionic radii

Choose the most appropriate answer from the options given below :

Answer
(B)
(A), (C) and (D) only
18
The reaction at cathode in the cells commonly used in clocks involves.
Answer
(B)
reduction of $$\mathrm{Mn}$$ from +4 to +3
19

The following reaction occurs in the Blast furnance where iron ore is reduced to iron metal

$$\mathrm{Fe}_2 \mathrm{O}_{3(s)}+3 \mathrm{CO}_{(g)} \rightleftharpoons \mathrm{Fe}_{(\mathrm{l})}+3 \mathrm{CO}_{2(g)}$$

Using the Le-chatelier's principle, predict which one of the following will not disturb the equilibrium.

Answer
(C)
Addition of $$\mathrm{Fe}_2 \mathrm{O}_3$$
20

Identify compound (Z) in the following reaction sequence.

JEE Main 2024 (Online) 5th April Morning Shift Chemistry - Compounds Containing Nitrogen Question 19 English

Answer
(B)
JEE Main 2024 (Online) 5th April Morning Shift Chemistry - Compounds Containing Nitrogen Question 19 English Option 2
21

The spin-only magnetic moment value of the ion among $$\mathrm{Ti}^{2+}, \mathrm{V}^{2+}, \mathrm{Co}^{3+}$$ and $$\mathrm{Cr}^{2+}$$, that acts as strong oxidising agent in aqueous solution is _________ BM (Near integer).

(Given atomic numbers : $$\mathrm{Ti}: 22, \mathrm{~V}: 23, \mathrm{Cr}: 24, \mathrm{Co}: 27$$)

Answer
5
22
The heat of combustion of solid benzoic acid at constant volume is $$-321.30 \mathrm{~kJ}$$ at $$27^{\circ} \mathrm{C}$$. The heat of combustion at constant pressure is $$(-321.30-x \mathrm{R}) \mathrm{~kJ}$$, the value of $$x$$ is __________.
Answer
150
23

JEE Main 2024 (Online) 5th April Morning Shift Chemistry - d and f Block Elements Question 21 English

In a borax bead test under hot condition, a metal salt (one from the given) is heated at point B of the flame, resulted in green colour salt bead. The spin-only magnetic moment value of the salt is _______ BM (Nearest integer) [Given atomic number of $$\mathrm{Cu}=29, \mathrm{Ni}=28, \mathrm{Mn}=25, \mathrm{Fe}=26$$]

Answer
6
24

The number of halobenzenes from the following that can be prepared by Sandmeyer's reaction is _________

JEE Main 2024 (Online) 5th April Morning Shift Chemistry - Haloalkanes and Haloarenes Question 14 English

Answer
2
25

An artificial cell is made by encapsulating $$0.2 \mathrm{~M}$$ glucose solution within a semipermeable membrane. The osmotic pressure developed when the artificial cell is placed within a $$0.05 \mathrm{~M}$$ solution of $$\mathrm{NaCl}$$ at $$300 \mathrm{~K}$$ is ________ $$\times 10^{-1}$$ bar. (nearest integer).

[Given : $$\mathrm{R}=0.083 \mathrm{~L} \mathrm{~bar} \mathrm{~mol}^{-1} \mathrm{~K}^{-1}$$ ]

Assume complete dissociation of $$\mathrm{NaCl}$$

Answer
25
26
In the lewis dot structure for $$\mathrm{NO}_2^{-}$$, total number of valence electrons around nitrogen is _________.
Answer
8
27
The value of Rydberg constant $$(R_H)$$ is $$2.18 \times 10^{-18} \mathrm{~J}$$. The velocity of electron having mass $$9.1 \times 10^{-31} \mathrm{~kg}$$ in Bohr's first orbit of hydrogen atom = ________ $$\times 10^5 \mathrm{~ms}^{-1}$$ (nearest integer).
Answer
22
28
$$9.3 \mathrm{~g}$$ of pure aniline is treated with bromine water at room temperature to give a white precipitate of the product '$$\mathrm{P}$$'. The mass of product '$$\mathrm{P}$$' obtained is $$26.4 \mathrm{~g}$$. The percentage yield is ________ %.
Answer
80
29

Consider the given chemical reaction sequence :

JEE Main 2024 (Online) 5th April Morning Shift Chemistry - Alcohols, Phenols and Ethers Question 10 English

Total sum of oxygen atoms in Product A and Product B are ________.

Answer
14
30

During Kinetic study of reaction $$\mathrm{2 A+B \rightarrow C+D}$$, the following results were obtained :

$$\mathrm{A [M]}$$ $$\mathrm{B [M]}$$ initial rate of formation of $$\mathrm{D}$$
I 0.1 0.1 $$6.0\times10^{-3}$$
II 0.3 0.2 $$7.2\times10^{-2}$$
III 0.3 0.4 $$2.88\times10^{-1}$$
IV 0.4 0.1 $$2.40\times10^{-2}$$

Based on above data, overall order of the reaction is _________.

Answer
3