JEE Main 2023 (Online) 30th January Evening Shift
JEE Main / 30 questions
2026Mon, Jan 30, 2023 9:30 AM30 PYQs
1Alcohols Phenols And Ethers
The correct order of $\mathrm{pK}_{\mathrm{a}}$ values for the following compounds is:
MCQ+4 / -12023
2Aldehydes Ketones And Carboxylic Acids
Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: can be easily reduced using $\mathrm{Zn}-\mathrm{Hg} / \mathrm{HCl}$ to
Reason $\mathrm{R}: \mathrm{Zn}-\mathrm{Hg} / \math...
Assertion A: can be easily reduced using $\mathrm{Zn}-\mathrm{Hg} / \mathrm{HCl}$ to
Reason $\mathrm{R}: \mathrm{Zn}-\mathrm{Hg} / \math...
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3Aldehydes Ketones And Carboxylic Acids
Number of compounds from the following which will not dissolve in cold $\mathrm{NaHCO}_{3}$ and $\mathrm{NaOH}$ solutions but will dissolve in hot $\mathrm{NaOH}$ solution is ________.
INTEGER+4 / -12023
4Basics Of Organic Chemistry
Match List I with List II:
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overflow:hidden;padding:10px 5px;word-break:normal;}...
MCQ+4 / -12023
5Biomolecules
A short peptide on complete hydrolysis produces 3 moles of glycine (G), two moles of leucine (L) and two moles of valine (V) per mole of peptide. The number of peptide linkages in it are ________.
INTEGER+4 / -12023
6Chemical Equilibrium
Consider the following equation:
$2 \mathrm{SO}_{2}(g)+\mathrm{O}_{2}(g) \rightleftharpoons 2 \mathrm{SO}_{3}(g), \Delta H=-190 \mathrm{~kJ}$
The number of factors which will increase the yield of $\mathrm{SO}_{3}$ at equilibrium from th...
$2 \mathrm{SO}_{2}(g)+\mathrm{O}_{2}(g) \rightleftharpoons 2 \mathrm{SO}_{3}(g), \Delta H=-190 \mathrm{~kJ}$
The number of factors which will increase the yield of $\mathrm{SO}_{3}$ at equilibrium from th...
INTEGER+4 / -12023
7Chemical Kinetics And Nuclear Chemistry
An organic compound undergoes first-order decomposition. If the time taken for the $60 \%$ decomposition is $540 \mathrm{~s}$, then the time required for $90 \%$ decomposition will be ________ s. (Nearest integer).
Given: $\ln 10=2.3 ; \lo...
Given: $\ln 10=2.3 ; \lo...
INTEGER+4 / -12023
8Chemistry In Everyday Life
Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason $\mathbf{R}$.
Assertion A: Antihistamines do not affect the secretion of acid in stomach.
Reason $\mathbf{R}$ : Antiallergic and antacid dr...
Assertion A: Antihistamines do not affect the secretion of acid in stomach.
Reason $\mathbf{R}$ : Antiallergic and antacid dr...
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9Compounds Containing Nitrogen
The most stable carbocation for the following is:
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10Compounds Containing Nitrogen
In the above conversion of compound $(\mathrm{X})$ to product $(\mathrm{Y})$, the sequence of reagents to be used will be:
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11Coordination Compounds
Match List I with List II:
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overflow:hidden;padding:10px 5px;word-break:normal;}...
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overflow:hidden;padding:10px 5px;word-break:normal;}...
MCQ+4 / -12023
12Coordination Compounds
The $\mathrm{Cl}-\mathrm{Co}-\mathrm{Cl}$ bond angle values in a fac- $\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{3} \mathrm{Cl}_{3}\right]$ complex is/are :
MCQ+4 / -12023
13D And F Block Elements
Formulae for Nessler's reagent is :
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14D And F Block Elements
$\mathrm{KMnO}_4$ oxidises $\mathrm{I}^{-}$ in acidic and neutral/faintly alkaline solutions, respectively, to :
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15Electrochemistry
The electrode potential of the following half cell at $298 \mathrm{~K}$
$\mathrm{X}\left|\mathrm{X}^{2+}(0.001 \mathrm{M}) \| \mathrm{Y}^{2+}(0.01 \mathrm{M})\right| \mathrm{Y}$ is _______ $\times 10^{-2} \mathrm{~V}$ (Nearest integer)
Gi...
$\mathrm{X}\left|\mathrm{X}^{2+}(0.001 \mathrm{M}) \| \mathrm{Y}^{2+}(0.01 \mathrm{M})\right| \mathrm{Y}$ is _______ $\times 10^{-2} \mathrm{~V}$ (Nearest integer)
Gi...
INTEGER+4 / -12023
16Environmental Chemistry
The water quality of a pond was analyzed and its BOD was found to be 4. The pond has :
MCQ+4 / -12023
17Haloalkanes And Haloarenes
Decreasing order towards SN 1 reaction for the following compounds is:
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18Isolation Of Elements
Given below are two statements:
Statement I: During Electrolytic refining, the pure metal is made to act as anode and its impure metallic form is used as cathode.
Statement II: During the Hall-Heroult electrolysis process, purified $\math...
Statement I: During Electrolytic refining, the pure metal is made to act as anode and its impure metallic form is used as cathode.
Statement II: During the Hall-Heroult electrolysis process, purified $\math...
MCQ+4 / -12023
19P Block Elements
Boric acid is solid, whereas $\mathrm{BF}_3$ is gas at room temperature because of :
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20Periodic Table And Periodicity
Bond dissociation energy of "E-H" bond of the "$\mathrm{H}_{2} \mathrm{E}$ " hydrides of group 16 elements (given below), follows order.
A. $\mathrm{O}$
B. $\mathrm{S}$
C. Se
D. $\mathrm{Te}$
Choose the correct from the options given below...
A. $\mathrm{O}$
B. $\mathrm{S}$
C. Se
D. $\mathrm{Te}$
Choose the correct from the options given below...
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21S Block Elements
Chlorides of which metal are soluble in organic solvents :
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22S Block Elements
Which of the following reaction is correct?
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23Solid State
Iron oxide FeO, crystallises in a cubic lattice with a unit cell edge length of 5.0 Å. If density of the $\mathrm{FeO}$ in the crystal is $4.0 \mathrm{~g} \mathrm{~cm}^{-3}$, then the number of $\mathrm{FeO}$ units present per unit cell is ...
INTEGER+4 / -12023
24Solutions
Lead storage battery contains $38 \%$ by weight solution of $\mathrm{H}_{2} \mathrm{SO}_{4}$. The van't Hoff factor is $2.67$ at this concentration. The temperature in Kelvin at which the solution in the battery will freeze is ________. (Ne...
INTEGER+4 / -12023
25Some Basic Concepts Of Chemistry
$1 \mathrm{~L}, 0.02 \mathrm{M}$ solution of $\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{5} \mathrm{SO}_{4}\right]$ Br is mixed with $1 \mathrm{~L}, 0.02 \mathrm{M}$ solution of $\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{5} \mathrm...
MCQ+4 / -12023
26Some Basic Concepts Of Chemistry
The strength of 50 volume solution of hydrogen peroxide is ______ $\mathrm{g} / \mathrm{L}$ (Nearest integer).
Given:
Molar mass of $\mathrm{H}_{2} \mathrm{O}_{2}$ is $34 \mathrm{~g} \mathrm{~mol}^{-1}$
Molar volume of gas at $\mathrm{ST...
Given:
Molar mass of $\mathrm{H}_{2} \mathrm{O}_{2}$ is $34 \mathrm{~g} \mathrm{~mol}^{-1}$
Molar volume of gas at $\mathrm{ST...
INTEGER+4 / -12023
27Structure Of Atom
Maximum number of electrons that can be accommodated in shell with $n=4$ are:
MCQ+4 / -12023
28Structure Of Atom
The wave function $(\Psi)$ of $2 \mathrm{~s}$ is given by
\(\Psi_{2 \mathrm{~s}}=\frac{1}{2 \sqrt{2 \pi}}\left(\frac{1}{a_0}\right)^{1 / 2}\left(2-\frac{r}{a_0}\right) e^{-r / 2 a_0}\)
At $r=r_0$, radial node is formed. Thus, $r_0$ in ter...
\(\Psi_{2 \mathrm{~s}}=\frac{1}{2 \sqrt{2 \pi}}\left(\frac{1}{a_0}\right)^{1 / 2}\left(2-\frac{r}{a_0}\right) e^{-r / 2 a_0}\)
At $r=r_0$, radial node is formed. Thus, $r_0$ in ter...
MCQ+4 / -12023
29Surface Chemistry
The graph of $\log \frac{x}{m}$ vs $\log \mathrm{p}$ for an adsorption process is a straight line inclined at an angle of $45^{\circ}$ with intercept equal to $0.6020$. The mass of gas adsorbed per unit mass of adsorbent at the pressure of ...
INTEGER+4 / -12023
30Thermodynamics
1 mole of ideal gas is allowed to expand reversibly and adiabatically from a temperature of $27^{\circ} \mathrm{C}$. The work done is $3 \mathrm{~kJ} \mathrm{~mol}^{-1}$. The final temperature of the gas is ________ $\mathrm{K}$ (Nearest in...
INTEGER+4 / -12023
