JEE MAIN - Chemistry (2024 - 1st February Morning Shift)

1
Which of the following reactions are disproportionation reactions?

(A) $\mathrm{Cu}^{+} \rightarrow \mathrm{Cu}^{2+}+\mathrm{Cu}$

(B) $3 \mathrm{MnO}_4^{2-}+4 \mathrm{H}^{+} \longrightarrow 2

\mathrm{MnO}_4^{-}+\mathrm{MnO}_2+2 \mathrm{H}_2 \mathrm{O}$

(C) $2 \mathrm{KMnO}_4 \longrightarrow \mathrm{K}_2 \mathrm{MnO}_4+\mathrm{MnO}_2+\mathrm{O}_2$

(D) $2 \mathrm{MnO}_4^{-}+3 \mathrm{Mn}^{2+}+2 \mathrm{H}_2 \mathrm{O} \longrightarrow 5 \mathrm{MnO}_2+4 \mathrm{H}^{+}$

Choose the correct answer from the options given below :
Answer
(A)
(A), (B)
2
Choose the correct option for free expansion of an ideal gas under adiabatic condition from the following :
Answer
(A)
$\mathrm{q}=0, \Delta \mathrm{T}=0, \mathrm{w}=0$
3
Identify $A$ and $B$ in the following sequence of reaction

JEE Main 2024 (Online) 1st February Morning Shift Chemistry - Aldehydes, Ketones and Carboxylic Acids Question 44 English
Answer
(B)
JEE Main 2024 (Online) 1st February Morning Shift Chemistry - Aldehydes, Ketones and Carboxylic Acids Question 44 English Option 2
4
Which of the following complex is homoleptic?
Answer
(D)
$\left[\mathrm{Ni}(\mathrm{CN})_4\right]^{2-}$
5
In Kjeldahl's method for estimation of nitrogen, $\mathrm{CuSO}_4$ acts as :
Answer
(A)
catalytic agent
6
Given below are two statements :

Statement (I) : Potassium hydrogen phthalate is a primary standard for standardisation of sodium hydroxide solution.

Statement (II) : In this titration phenolphthalein can be used as indicator.

In the light of the above statements, choose the most appropriate answer from the options given below :
Answer
(A)
Both Statement I and Statement II are correct
7
In case of isoelectronic species the size of $\mathrm{F}^{-}, \mathrm{Ne}$ and $\mathrm{Na}^{+}$is affected by :
Answer
(A)
Nuclear charge $(\mathrm{z})$
8
Ionic reactions with organic compounds proceed through :

(A) homolytic bond cleavage

(B) heterolytic bond cleavage

(C) free radical formation

(D) primary free radical

(E) secondary free radical

Choose the correct answer from the options given below :
Answer
(B)
(B) only
9
Which of the following compound will most easily be attacked by an electrophile?
Answer
(B)
JEE Main 2024 (Online) 1st February Morning Shift Chemistry - Basics of Organic Chemistry Question 74 English Option 2
10
Given below are two statements :

Statement (I) : A solution of $\left[\mathrm{Ni}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+}$ is green in colour.

Statement (II) : A solution of $\left[\mathrm{Ni}(\mathrm{CN})_4\right]^{2-}$ is colourless.

In the light of the above statements, choose the most appropriate answer from the options given below :
Answer
(B)
Both Statement I and Statement II are correct
11
We have three aqueous solutions of $\mathrm{NaCl}$ labelled as ' $\mathrm{A}$ ', ' $\mathrm{B}$ ' and ' $\mathrm{C}$ ' with concentration $0.1 \mathrm{M}$, $0.01 \mathrm{M}$ and $0.001 \mathrm{M}$, respectively. The value of van 't Hoff factor(i) for these solutions will be in the order :
Answer
(B)
$\mathrm{i}_{\mathrm{A}}<\mathrm{i}_{\mathrm{B}}<\mathrm{i}_{\mathrm{C}}$
12
Given below are two statements :

Statement (I) : The $\mathrm{NH}_2$ group in Aniline is ortho and para directing and a powerful activating group.

Statement (II) : Aniline does not undergo Friedel-Craft's reaction (alkylation and acylation).

In the light of the above statements, choose the most appropriate answer from the options given below :
Answer
(A)
Both Statement I and Statement II are correct
13
According to the wave-particle duality of matter by de-Broglie, which of the following graph plot presents most appropriate relationship between wavelength of electron $(\lambda)$ and momentum of electron $(p)$?
Answer
(D)
JEE Main 2024 (Online) 1st February Morning Shift Chemistry - Structure of Atom Question 32 English Option 4
14
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A): $\mathrm{PH}_3$ has lower boiling point than $\mathrm{NH}_3$.

Reason (R) : In liquid state $\mathrm{NH}_3$ molecules are associated through vander Waal's forces, but $\mathrm{PH}_3$ molecules are associated through hydrogen bonding.

In the light of the above statements, choose the most appropriate answer from the options given below :
Answer
(C)
(A) is correct but (R) is not correct
15
Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A) : Haloalkanes react with KCN to form alkyl cyanides as a main product while with $\mathrm{AgCN}$ form isocyanide as the main product.

Reason (R) : $\mathrm{KCN}$ and $\mathrm{AgCN}$ both are highly ionic compounds.

In the light of the above statements, choose the most appropriate answer from the options given below :
Answer
(A)
(A) is correct but $(\mathbf{R})$ is not correct
16
If one strand of a DNA has the sequence ATGCTTCA, sequence of the bases in complementary strand is :
Answer
(B)
TACGAAGT
17
In acidic medium, $\mathrm{K}_2 \mathrm{Cr}_2 \mathrm{O}_7$ shows oxidising action as represented in the half reaction:

$$ \mathrm{Cr}_2 \mathrm{O}_7{ }^{2-}+\mathrm{XH}^{+}+\mathrm{Ye}^{\ominus} \rightarrow 2 \mathrm{~A}+\mathrm{ZH}_2 \mathrm{O} $$

$\mathrm{X}, \mathrm{Y}, \mathrm{Z}$ and $\mathrm{A}$ are respectively are :
Answer
(B)
$14,6,7$ and $\mathrm{Cr}^{3+}$
18
Given below are two statements :

Statement (I) : Aminobenzene and aniline are same organic compounds.

Statement (II) : Aminobenzene and aniline are different organic compounds.

In the light of the above statements, choose the most appropriate answer from the options given below :
Answer
(C)
Statement I is correct but Statement II is incorrect
19
Match List - I with List - II.

List I (Reactions) List II (Reagents)
(A) JEE Main 2024 (Online) 1st February Morning Shift Chemistry - Aldehydes, Ketones and Carboxylic Acids Question 43 English 1 (I) CH3MgBr, H2O
(B) C6H5COC6H5 ⟶ C6H5CH=C6H5 (II) Zn(Hg) and conc. HCl
(C) C6H5CHO ⟶ C6H5CH(OH)CH3 (III) NaBH4, H+
(D) JEE Main 2024 (Online) 1st February Morning Shift Chemistry - Aldehydes, Ketones and Carboxylic Acids Question 43 English 2 (IV) DIBAL-H, H2O


Choose the correct answer from the options given below :
Answer
(C)
(A)-(IV), (B)-(II), (C)-(I), (D)-(III)
20
Arrange the bonds in order of increasing ionic character in the molecules. $\mathrm{LiF}$, $\mathrm{K}_2 \mathrm{O}, \mathrm{N}_2, \mathrm{SO}_2$ and $\mathrm{ClF}_3$ :
Answer
(A)
$\mathrm{N}_2<\mathrm{SO}_2<\mathrm{ClF}_3<\mathrm{K}_2 \mathrm{O}<\mathrm{LiF}$
21
The number of white coloured salts, among the following is

(a) $\mathrm{SrSO}_4$

(b) $\mathrm{Mg}\left(\mathrm{NH}_4\right) \mathrm{PO}_4$

(c) $\mathrm{BaCrO}_4$

(d) $\mathrm{Mn}(\mathrm{OH})_2$

(e) $\mathrm{PbSO}_4$

(f) $\mathrm{PbCrO}_4$

(g) $\mathrm{AgBr}$

(h) $\mathrm{PbI}_2$

(i) $\mathrm{CaC}_2 \mathrm{O}_4$

(j) $\left[\mathrm{Fe}(\mathrm{OH})_2\left(\mathrm{CH}_3 \mathrm{COO}\right)\right]$
Answer
5
22
Total number of deactivating groups in aromatic electrophilic substitution reaction among the following is _______ .

JEE Main 2024 (Online) 1st February Morning Shift Chemistry - Basics of Organic Chemistry Question 73 English
Answer
2
23
The potential for the given half cell at $298 \mathrm{~K}$ is (-) __________ $\times 10^{-2} \mathrm{~V}$

$$ \begin{aligned} & 2 \mathrm{H}_{(\mathrm{aq})}^{+}+2 \mathrm{e}^{-} \longrightarrow \mathrm{H}_2(\mathrm{~g}) \\\\ & {\left[\mathrm{H}^{+}\right]=1 \mathrm{M}, \mathrm{P}_{\mathrm{H}_2}=2 \mathrm{~atm}} \end{aligned} $$

(Given : $2.303 \mathrm{RT} / \mathrm{F}=0.06 \mathrm{~V}, \log 2=0.3$ )
Answer
1
24
Among the following oxides of p-block elements, number of oxides having amphoteric nature is ________.

$\mathrm{Cl}_2 \mathrm{O}_7, \mathrm{CO}, \mathrm{PbO}_2, \mathrm{~N}_2 \mathrm{O}, \mathrm{NO}, \mathrm{Al}_2 \mathrm{O}_3, \mathrm{SiO}_2, \mathrm{~N}_2 \mathrm{O}_5, \mathrm{SnO}_2$
Answer
3
25
Consider the following reaction :

$$ 3 \mathrm{PbCl}_2+2\left(\mathrm{NH}_4\right)_3 \mathrm{PO}_4 \rightarrow \mathrm{Pb}_3\left(\mathrm{PO}_4\right)_2+6 \mathrm{NH}_4 \mathrm{Cl} $$

If $72 ~\mathrm{mmol}$ of $\mathrm{PbCl}_2$ is mixed with $50 ~\mathrm{mmol}$ of $\left(\mathrm{NH}_4\right)_3 \mathrm{PO}_4$, then the amount of $\mathrm{Pb}_3\left(\mathrm{PO}_4\right)_2$ formed is ________ mmol (nearest integer).
Answer
24
26
The number of molecules/ion/s having trigonal bipyramidal shape is _______.

$\mathrm{PF}_5, \mathrm{BrF}_5, \mathrm{PCl}_5,\left[\mathrm{Pt} \mathrm{Cl}_4\right]^{2-}, \mathrm{BF}_3, \mathrm{Fe}(\mathrm{CO})_5$
Answer
3
27
The lowest oxidation number of an atom in a compound $\mathrm{A}_2 \mathrm{B}$ is -2 . The number of electrons in its valence shell is _______.
Answer
6
28
$\mathrm{K}_{\mathrm{a}}$ for $\mathrm{CH}_3 \mathrm{COOH}$ is $1.8 \times 10^{-5}$ and $\mathrm{K}_{\mathrm{b}}$ for $\mathrm{NH}_4 \mathrm{OH}$ is $1.8 \times 10^{-5}$. The $\mathrm{pH}$ of ammonium acetate solution will be _________.
Answer
7
29
Number of optical isomers possible for 2-chlorobutane ________.
Answer
2
30
The ratio of $\frac{{ }^{14} \mathrm{C}}{{ }^{12} \mathrm{C}}$ in a piece of wood is $\frac{1}{8}$ part that of atmosphere. If half life of ${ }^{14} \mathrm{C}$ is 5730 years, the age of wood sample is ________ years.
Answer
17190