JEE MAIN - Chemistry (2025 - 4th April Evening Shift)
1
Given below are two statements:
Statement (I): For , all three possible structures may be drawn as follows.
Statement (II): Structure III is most stable, as the orbitals having the lone pairs are axial, where the lp ā bp repulsion is minimum.
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
2
Consider the following plots of $\log$ of rate constant $\mathrm{k}(\log \mathrm{k})$ vs $\frac{1}{\mathrm{~T}}$ for three different reactions. The correct order of activation energies of these reactions is :
Answer
(A)
$\mathrm{Ea}_2>\mathrm{Ea}_1>\mathrm{Ea}_3$
3
Match List - I with List - II
List - I (Separation of)
List - II (Separation Technique)
(A)
Aniline from aniline-water mixture
(I)
Simple distillation
(B)
Glycerol from spent-lye in soap industry
(II)
Fractional distillation
(C)
Different fractions of crude oil in petroleum industry
(III)
Distillation at reduced pressure
(D)
Chloroform-Aniline mixture
(IV)
Steam distillation
Choose the correct answer from the options given below :
Answer
(A)
(A)-(IV), (B)-(III), (C)-(II), (D)-(I)
4
Given below are two statements :
Statement (I) : The first ionisation enthalpy of group 14 elements is higher than the corresponding elements of group 13.
Statement (II) : Melting points and boiling points of group 13 elements are in general much higher than those of corresponding elements of group 14.
In the light of the above statements, choose the most appropriate answer from the options given below :
Answer
(A)
Statement I is correct but Statement II is incorrect
5
Which among the following compounds give yellow solid when reacted with $\mathrm{NaOI} / \mathrm{NaOH}$ ?
Choose the correct answer from the options given below :
Answer
(A)
(A) and (C) Only
6
Consider the ground state of chromium atom $(Z=24)$. How many electrons are with Azimuthal quantum number $l=1$ and $l=2$ respectively ?
Answer
(B)
12 and 5
7
Given below are two statements:
Statement (I) : Molal depression constant $\mathrm{K}_f$ is given by $\frac{\mathrm{M}_1 \mathrm{RT}_f}{\Delta \mathrm{~S}_{\mathrm{fus}}}$, where symbols have their usual meaning.
Statement (II) : $\mathrm{K}_f$ for benzene is less than the $\mathrm{K}_f$ for water.
In the light of the above statements, choose the most appropriate answer from the options given below :
Answer
(A)
Statement I is correct but Statement II is incorrect
8
The IUPAC name of the following compound is:
Answer
(B)
Hept-1-en-6-yn-4-ol
9
Half life of zero order reaction $\mathrm{A} \rightarrow$ product is 1 hour, when initial concentration of reactant is $2.0 \mathrm{~mol} \mathrm{~L}{ }^{-1}$. The time required to decrease concentration of A from 0.50 to $0.25 \mathrm{~mol} \mathrm{~L}^{-1}$ is :
Answer
(B)
15 min
10
The incorrect relationship in the following pairs in relation to ionisation enthalpies is :
Answer
(A)
$\mathrm{Mn}^{2+}<\mathrm{Fe}^{2+}$
11
A toxic compound " A " when reacted with NaCN in aqueous acidic medium yields an edible cooking component and food preservative " B ". " B " is converted to " C " by diborane and can be used as an additive to petrol to reduce emission. "C" upon reaction with oleum at $140^{\circ} \mathrm{C}$ yields an inhalable anesthetic " D ". Identify " A ", " B ", " C " & " D ", respectively :
Answer
(A)
Methanol; acetic acid; ethanol; diethyl ether
12
In which pairs, the first ion is more stable than the second?
Answer
(A)
(A) & (B) only
13
' $X$ ' is the number of electrons in $t_{2 g}$ orbitals of the most stable complex ion among $\left[\mathrm{Fe}\left(\mathrm{NH}_3\right)_6\right]^{3+},\left[\mathrm{FeCl}_6\right]^{3-}, \quad\left[\mathrm{Fe}\left(\mathrm{C}_2 \mathrm{O}_4\right)_3\right]^{3-}$ and $\left[\mathrm{Fe}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{3+}$. The nature of oxide of vanadium of the type $\mathrm{V}_2 \mathrm{O}_{\mathrm{X}}$ is :
Answer
(A)
Amphoteric
14
The correct order of basicity for the following molecules is :
The heat of solution depends on the amount of solvent.
16
Consider the following molecule(X).
The major product formed when the given molecule $(X)$ is treated with $\mathrm{HBr}(1 \mathrm{eq})$ is :
Answer
(A)
17
The correct order of $\left[\mathrm{FeF}_6\right]^{3-},\left[\mathrm{CoF}_6\right]^{3-},\left[\mathrm{Ni}(\mathrm{CO})_4\right]$ and $\left[\mathrm{Ni}(\mathrm{CN})_4\right]^{2-}$ complex species based on the number of unpaired electrons present is:
Statement (I) : Alcohols are formed when alkyl chlorides are treated with aqueous potassium hydroxide by elimination reaction.
Statement (II) : In alcoholic potassium hydroxide, alkyl chlorides form alkenes by abstracting the hydrogen from the $\beta$-carbon.
In the light of the above statements, choose the most appropriate answer from the options given below :
Answer
(C)
Statement I is incorrect but Statement II is correct
19
A dipeptide, " $x$ " on complete hydrolysis gives " $y$ " and " $z$ ". " $y$ " on treatment with aq. $\mathrm{HNO}_2$ produces lactic acid. On the other hand " z " on heating gives the following cyclic molecule.
Based on the information given, the dipeptide $X$ is :
Answer
(D)
alanine-glycine
20
The elements of Group 13 with highest and lowest first ionisation enthalpies are respectively :
Answer
(C)
$B ~\& ~\operatorname{In}$
21
Sea water, which can be considered as a 6 molar $(6 \mathrm{M})$ solution of NaCl , has a density of $2 \mathrm{~g} \mathrm{~mL}^{-1}$. The concentration of dissolved oxygen $\left(\mathrm{O}_2\right)$ in sea water is 5.8 ppm . Then the concentration of dissolved oxygen $\left(\mathrm{O}_2\right)$ in sea water, is $x \times 10^{-4} \mathrm{~m}$.
$x=$ ___________. (Nearest integer)
Given: Molar mass of NaCl is $58.5 \mathrm{~g} \mathrm{~mol}^{-1}$
Molar mass of $\mathrm{O}_2$ is $32 \mathrm{~g} \mathrm{~mol}^{-1}$
Answer
2
22
The amount of calcium oxide produced on heating 150 kg limestone ( $75 \%$ pure) is
_________ kg. (Nearest integer)
Given: Molar mass (in $\mathrm{g} \mathrm{mol}^{-1}$ ) of Ca-40, O-16, C-12
Answer
63
23
A metal complex with a formula $\mathrm{MCl}_4 \cdot 3 \mathrm{NH}_3$ is involved in $\mathrm{sp}^3 \mathrm{~d}^2$ hybridisation. It upon reaction with excess of $\mathrm{AgNO}_3$ solution gives ' $x$ ' moles of AgCl . Consider ' $x$ ' is equal to the number of lone pairs of electron present in central atom of $\mathrm{BrF}_5$. Then the number of geometrical isomers exhibited by the complex is _________.
Answer
2
24
The molar conductance of an infinitely dilute solution of ammonium chloride was found to be $185 \mathrm{~S} \mathrm{~cm}^2 \mathrm{~mol}^{-1}$ and the ionic conductance of hydroxyl and chloride ions are 170 and $70 \mathrm{~S} \mathrm{~cm}^2 \mathrm{~mol}^{-1}$, respectively. If molar conductance of 0.02 M solution of ammonium hydroxide is $85.5 \mathrm{~S} \mathrm{~cm}^2 \mathrm{~mol}^{-1}$, its degree of dissociation is given by $x \times 10^{-1}$.
The value of $x$ is __________ . (Nearest integer)
Answer
3
25
$x \mathrm{mg}$ of $\mathrm{Mg}(\mathrm{OH})_2($ molar mass $=58)$ is required to be dissolved in 1.0 L of water to produce a pH of 10.0 at 298 K . The value of $x$ is ________ mg. (Nearest integer)
(Given : $\mathrm{Mg}(\mathrm{OH})_2$ is assumed to dissociate completely in $\mathrm{H}_2 \mathrm{O}$ ]