JEE MAIN - Chemistry (2024 - 30th January Morning Shift)

1
Aluminium chloride in acidified aqueous solution forms an ion having geometry
Answer
(B)
Octahedral
2
Example of vinylic halide is :
Answer
(D)
JEE Main 2024 (Online) 30th January Morning Shift Chemistry - Haloalkanes and Haloarenes Question 24 English Option 4
3

Given below are two statements :

Statement (I) : The gas liberated on warming a salt with dil $$\mathrm{H}_2 \mathrm{SO}_4$$, turns a piece of paper dipped in lead acetate into black, it is a confirmatory test for sulphide ion.

Statement (II) : In statement-I the colour of paper turns black because of formation of lead sulphite. In the light of the above statements, choose the most appropriate answer from the options given below :

Answer
(B)
Statement I is true but Statement II is false
4

The final product A, formed in the following multistep reaction sequence is :

JEE Main 2024 (Online) 30th January Morning Shift Chemistry - Haloalkanes and Haloarenes Question 25 English

Answer
(C)
JEE Main 2024 (Online) 30th January Morning Shift Chemistry - Haloalkanes and Haloarenes Question 25 English Option 3
5

JEE Main 2024 (Online) 30th January Morning Shift Chemistry - Aldehydes, Ketones and Carboxylic Acids Question 32 English

This reduction reaction is known as:

Answer
(D)
Rosenmund reduction
6

Compound A formed in the following reaction reacts with B gives the product C. Find out A and B.

JEE Main 2024 (Online) 30th January Morning Shift Chemistry - Hydrocarbons Question 25 English

Answer
(A)
$$\mathrm{A}=\mathrm{CH}_3-\mathrm{C} \equiv \stackrel{-}{\mathrm{C}} \mathrm{Na}^{+}, \mathrm{B}=\mathrm{CH}_3-\mathrm{CH}_2-\mathrm{CH}_2-\mathrm{Br}$$
7
Which of the following molecule/species is most stable?
Answer
(B)
JEE Main 2024 (Online) 30th January Morning Shift Chemistry - Basics of Organic Chemistry Question 47 English Option 2
8
What happens to freezing point of benzene when small quantity of napthalene is added to benzene?
Answer
(B)
Decreases
9

Match List I with List II.

List I
Molecule
List II
Shape
(A) $$\mathrm{BrF_5}$$ (I) T-Shape
(B) $$\mathrm{H_2O}$$ (II) See saw
(C) $$\mathrm{ClF_3}$$ (III) Bent
(D) $$\mathrm{SF_4}$$ (IV) Square pyramidal

Choose the correct answer from the options given below :

Answer
(B)
(A)-(IV), (B)-(III), (C)-(I), (D)-(II)
10

Match List I with List II.

List I
Species
List II
Electronic distribution
(A) $$\mathrm{Cr^{+2}}$$ (I) $$\mathrm{3d^8}$$
(B) $$\mathrm{Mn^+}$$ (II) $$\mathrm{3d^34s^1}$$
(C) $$\mathrm{Ni^{+2}}$$ (III) $$\mathrm{3d^4}$$
(D) $$\mathrm{V^+}$$ (IV) $$\mathrm{3d^54s^1}$$

Choose the correct answer from the options given below :

Answer
(A)
(A)-(III), (B)-(IV), (C)-(I), (D)-(II)
11
The Lassiagne's extract is boiled with dil $$\mathrm{HNO}_3$$ before testing for halogens because,
Answer
(C)
$$\mathrm{Na}_2 \mathrm{S}$$ and $$\mathrm{NaCN}$$ are decomposed by $$\mathrm{HNO}_3$$.
12

Given below are two statements :

Statement (I) : The orbitals having same energy are called as degenerate orbitals.

Statement (II) : In hydrogen atom, 3p and 3d orbitals are not degenerate orbitals.

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

Answer
(A)
Statement I is true but Statement II is false
13
Sugar which does not give reddish brown precipitate with Fehling's reagent, is :
Answer
(B)
Sucrose
14

In the given reactions, identify the reagent A and reagent B.

JEE Main 2024 (Online) 30th January Morning Shift Chemistry - Hydrocarbons Question 24 English

Answer
(B)
$$\mathrm{A}-\mathrm{CrO}_3 \quad \mathrm{~B}-\mathrm{CrO}_2 \mathrm{Cl}_2$$
15
Diamagnetic Lanthanoid ions are :
Answer
(A)
$$\mathrm{La}^{3+} \& \mathrm{~Ce}^{4+}$$
16

Choose the correct statements from the following :

(A) Ethane-1, 2-diamine is a chelating ligand.

(B) Metallic aluminium is produced by electrolysis of aluminium oxide in presence of cryolite.

(C) Cyanide ion is used as ligand for leaching of silver.

(D) Phosphine act as a ligand in Wilkinson catalyst.

(E) The stability constants of $$\mathrm{Ca}^{2+}$$ and $$\mathrm{Mg}^{2+}$$ are similar with EDTA complexes.

Choose the correct answer from the options given below :

Answer
(D)
(A), (B), (C) only
17

Following is a confirmatory test for aromatic primary amines. Identify reagent (A) and (B).

JEE Main 2024 (Online) 30th January Morning Shift Chemistry - Compounds Containing Nitrogen Question 31 English

Answer
(A)
JEE Main 2024 (Online) 30th January Morning Shift Chemistry - Compounds Containing Nitrogen Question 31 English Option 1
18

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

Assertion (A) : $$\mathrm{CH}_2=\mathrm{CH}-\mathrm{CH}_2-\mathrm{Cl}$$ is an example of allyl halide.

Reason (R) : Allyl halides are the compounds in which the halogen atom is attached to $$\mathrm{sp}^2$$ hybridised carbon atom.

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

Answer
(A)
(A) is true but (R) is false
19

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

Assertion (A) : There is a considerable increase in covalent radius from $$\mathrm{N}$$ to $$\mathrm{P}$$. However from As to Bi only a small increase in covalent radius is observed.

Reason (R) : Covalent and ionic radii in a particular oxidation state increases down the group. In the light of the above statements, choose the most appropriate answer from the options given below:

Answer
(C)
Both (A) and (R) are true but (R) is not the correct explanation of (A)
20
Structure of 4-Methylpent-2-enal is :
Answer
(C)
JEE Main 2024 (Online) 30th January Morning Shift Chemistry - Aldehydes, Ketones and Carboxylic Acids Question 31 English Option 3
21
The total number of molecular orbitals formed from $$2 \mathrm{s}$$ and $$2 \mathrm{p}$$ atomic orbitals of a diatomic molecule is __________.
Answer
8
22
The mass of sodium acetate $$\left(\mathrm{CH}_3 \mathrm{COONa}\right)$$ required to prepare $$250 \mathrm{~mL}$$ of $$0.35 \mathrm{~M}$$ aqueous solution is ________ g. (Molar mass of $$\mathrm{CH}_3 \mathrm{COONa}$$ is $$82.02 \mathrm{~g} \mathrm{~mol}^{-1}$$)
Answer
7
23
$$0.05 \mathrm{~cm}$$ thick coating of silver is deposited on a plate of $$0.05 \mathrm{~m}^2$$ area. The number of silver atoms deposited on plate are ________ $$\times 10^{23}$$. (At mass $$\mathrm{Ag}=108, \mathrm{~d}=7.9 \mathrm{~g} \mathrm{~cm}^{-3}$$)
Answer
11
24
The compound formed by the reaction of ethanal with semicarbazide contains _________ number of nitrogen atoms.
Answer
3
25
The $$\mathrm{pH}$$ at which $$\mathrm{Mg}(\mathrm{OH})_2\left[\mathrm{~K}_{\mathrm{sp}}=1 \times 10^{-11}\right]$$ begins to precipitate from a solution containing $$0.10 \mathrm{~M} \mathrm{~Mg}^{2+}$$ ions is __________.
Answer
9
26

$$2 \mathrm{MnO}_4^{-}+\mathrm{bI}^{-}+\mathrm{cH}_2 \mathrm{O} \rightarrow x \mathrm{I}_2+y \mathrm{MnO}_2+z \overline{\mathrm{O}} \mathrm{H}$$

If the above equation is balanced with integer coefficients, the value of $$z$$ is ________.

Answer
8
27

JEE Main 2024 (Online) 30th January Morning Shift Chemistry - Thermodynamics Question 30 English

An ideal gas undergoes a cyclic transformation starting from the point A and coming back to the same point by tracing the path $$\mathrm{A} \rightarrow \mathrm{B} \rightarrow \mathrm{C} \rightarrow \mathrm{A}$$ as shown in the diagram above. The total work done in the process is __________ J.

Answer
200
28
The rate of First order reaction is $$0.04 \mathrm{~mol} \mathrm{~L}^{-1} \mathrm{~s}^{-1}$$ at 10 minutes and $$0.03 \mathrm{~mol} \mathrm{~L}^{-1} \mathrm{~s}^{-1}$$ at 20 minutes after initiation. Half life of the reaction is _______ minutes.

(Given $$\log 2=0.3010, \log 3=0.4771$$)
Answer
24
29
On a thin layer chromatographic plate, an organic compound moved by $$3.5 \mathrm{~cm}$$, while the solvent moved by $$5 \mathrm{~cm}$$. The retardation factor of the organic compound is ________ $$\times 10^{-1}$$.
Answer
7
30
If IUPAC name of an element is "Unununnium" then the element belongs to nth group of Periodic table. The value of n is ________.
Answer
11