JEE Main 2025 (Online) 29th January Evening Shift

Which one of the following, with HBr will give a phenol?

In the Claisen-Schmidt reaction to prepare, dibenzalacetone from 5.3 g of benzaldehyde, a total of 3.51 g of product was obtained. The percentage yield in this reaction was _______ %.

Given below are two statements :
Statement (I): On nitration of m-xylene with $\mathrm{HNO}_3, \mathrm{H}_2 \mathrm{SO}_4$ followed by oxidation, 4-nitrobenzene-1,3-dicarboxylic acid is obtained as the major product.
Statement (II) : $-\mat...

Identify the essential amino acids from below:(A) Valine(B) Proline(C) Lysine(D) Threonine(E) TyrosineChoose the correct answer from the options given below:

Total number of non-bonded electrons present in NO2$-$ ion based on Lewis theory is ______.

Consider the equilibrium
\(\mathrm{CO}(\mathrm{g})+3 \mathrm{H}_2(\mathrm{~g}) \rightleftharpoons \mathrm{CH}_4(\mathrm{~g})+\mathrm{H}_2 \mathrm{O}(\mathrm{~g})\)
If the pressure applied over the system increases by two fold at constant ...

Drug $X$ becomes ineffective after $50 \%$ decomposition. The original concentration of drug in a bottle was $16 \mathrm{mg} / \mathrm{mL}$ which becomes $4 \mathrm{mg} / \mathrm{mL}$ in 12 months. The expiry time of the drug in months is _...

Which one of the following reaction sequences will give an azo dye?

Identify the homoleptic complexes with odd number of $d$ electrons in the central metal :
(A) $\left[\mathrm{FeO}_4\right]^{2-}$
(B) $\left[\mathrm{Fe}(\mathrm{CN})_6\right]^{3-}$
(C) $\left[\mathrm{Fe}(\mathrm{CN})_5 \mathrm{NO}\right]^{2-...

The calculated spin-only magnetic moments of $K_3[Fe(OH)_6]$ and $K_4[Fe(OH)_6]$ respectively are :

Consider the following low-spin complexes
$$ \mathrm{K}_3\left[\mathrm{Co}\left(\mathrm{NO}_2\right)_6\right], \mathrm{K}_4\left[\mathrm{Fe}(\mathrm{CN})_6\right], \mathrm{K}_3\left[\mathrm{Fe}(\mathrm{CN})_6\right], \mathrm{Cu}_2\left[\mat...

Match List - I with List - II :

List - I (Applications)
List - II (Batteries/Cell)


(A) Transistors
(I) Anode - Zn/Hg; Cathode - HgO + C


(B) Hearing aids
(II) Hydrogen fuel cell


(C) Inverters
...

$\mathrm{O}_2$ gas will be evolved as a product of electrolysis of :
(A) an aqueous solution of $\mathrm{AgNO}_3$ using silver electrodes.
(B) an aqueous solution of $\mathrm{AgNO}_3$ using platinum electrodes.
(C) a dilute solution of $\ma...

Which among the following halides will generate the most stable carbocation in the nucleophilic substitution reaction?

Total number of sigma (σ) _______ and pi(π) ______ bonds respectively present in hex-1-en-4-yne are:

Isomeric hydrocarbons → negative Baeyer’s test(Molecular formula C9H12)The total number of isomers from above with four different non-aliphatic substitution sites is -

The type of oxide formed by the element among Li, Na, Be, Mg, B and Al that has the least atomic radius is :

First ionisation enthalpy values of first four group 15 elements are given below. Choose the correct value for the element that is a main component of apatite family :

Given below are two statements :
Statement (I): In partition chromatography, stationary phase is thin film of liquid present in the inert support.
Statement (II): In paper chromatography, the material of paper acts as a stationary phase.
In...

In the sulphur estimation, 0.20 g of a pure organic compound gave 0.40 g of barium sulphate. The percentage of sulphur in the compound is __________ $\times 10^{-1} \%$.
(Molar mass : $\mathrm{O}=16, \mathrm{~S}=32, \mathrm{Ba}=137$ in $\ma...

0.1 M solution of KI reacts with excess of $\mathrm{H}_2 \mathrm{SO}_4$ and $\mathrm{KIO}_3$ solutions. According to equation
\(5 \mathrm{I}^{-}+\mathrm{IO}_3^{-}+6 \mathrm{H}^{+} \rightarrow 3 \mathrm{I}_2+3 \mathrm{H}_2 \mathrm{O}\)
Ide...

Given below are two statements :
Statement (I): NaCl is added to the ice at 0°C, present in the ice cream box to prevent the melting of ice cream.
Statement (II): On addition of NaCl to ice at 0°C, there is a depression in freezing point.
I...

For hydrogen like species, which of the following graphs provides the most appropriate representation of E vs Z plot for a constant n?
[E : Energy of the stationary state, Z : atomic number, n = principal quantum number]

Given below are two statements :
Statement (I): It is impossible to specify simultaneously with arbitrary precision, both the linear momentum and the position of a particle.
Statement (II) : If the uncertainty in the measurement of position...

If $\quad C$ (diamond $) \rightarrow C$ (graphite) $+X \mathrm{~kJ} \mathrm{~mol}^{-1}$
C (diamond) $+\mathrm{O}_2(\mathrm{~g}) \rightarrow \mathrm{CO}_2(\mathrm{~g})+\mathrm{Y} \mathrm{kJ} \mathrm{mol}{ }^{-1}$
C (graphite) $+\mathrm{O}_2(...