JEE Main 2025 Apr 3 Shift 1 — Chemistry

Among $10^{-9}$ g (each) of the following elements, which one will have the highest number of atoms?

Element: Pb, Po, Pr and Pt

Which of the following postulate of Bohr's model of hydrogen atom is not in agreement with quantum mechanical model of an atom?

Which of the following properties will change when system containing solution 1 will become solution 2?

a box labelled “10 mol of solute x + 10 L of water” (Solution 1) with an arrow to a box labelled “1 L of solution 1 + 1 mol of solute x + 1 L of water” (Solution 2)

2 moles each of ethylene glycol and glucose are dissolved in 500 g of water. The boiling point of the resulting solution is:

(Given : Ebullioscopic constant of water $= 0.52~\mathrm{K~kg~mol^{-1}}$)

In the following system, $\mathrm{PCl_5(g) \rightleftharpoons PCl_3(g) + Cl_2(g)}$ at equilibrium, upon addition of xenon gas at constant T & p, the concentration of

Correct order of limiting molar conductivity for cations in water at 298 K is :

Given below are two statements:

Statement I : A catalyst cannot alter the equilibrium constant ($K_c$) of the reaction, temperature remaining constant.

Statement II : A homogenous catalyst can change the equilibrium composition of a system, temperature remaining constant.

In the light of the above statements, choose the correct answer from the options given below

In a reaction A + B $\rightarrow$ C, initial concentrations of A and B are related as $[A]_0 = 8[B]_0$. The half lives of A and B are 10 min and 40 min, respectively. If they start to disappear at the same time, both following first order kinetics, after how much time will the concentration of both the reactants be same ?

Match the LIST-I with LIST-II

	LIST-I (Molecules/ ion)		LIST-II (Hybridisation of central atom)
A.	$\mathrm{PF_5}$	I.	$dsp^2$
B.	$\mathrm{SF_6}$	II.	$sp^3d$
C.	$\mathrm{Ni(CO)_4}$	III.	$sp^3d^2$
D.	$\mathrm{[PtCl_4]^{2-}}$	IV.	$sp^3$

Choose the correct answer from the options given below:

Which of the following statements are correct ?

A. The process of adding an electron to a neutral gaseous atom is always exothermic. B. The process of removing an electron from an isolated gaseous atom is always endothermic. C. The 1$^{st}$ ionization energy of boron is less than that of beryllium. D. The electronegativity of C is 2.5 in $\mathrm{CH_4}$ and $\mathrm{CCl_4}$ E. Li is the most electropositive among elements of group I.

Choose the correct answer from the options given below:

Given below are two statements:

Statement I : The N - N single bond is weaker and longer than that of P - P single bond.

Statement II : Compounds of group 15 elements in + 3 oxidation states readily undergo disproportionation reactions.

In the light of the above statements, choose the correct answer from the options given below

The metal ions that have the calculated spin-only magnetic moment value of 4.9 B.M. are :

A. $\mathrm{Cr^{2+}}$ B. $\mathrm{Fe^{2+}}$ C. $\mathrm{Fe^{3+}}$ D. $\mathrm{Co^{2+}}$ E. $\mathrm{Mn^{3+}}$

Choose the correct answer from the options given below:

The correct order of the complexes $\mathrm{[Co(NH_3)_5(H_2O)]^{3+}}$ (A), $\mathrm{[Co(NH_3)_6]^{3+}}$ (B), $\mathrm{[Co(CN)_6]^{3-}}$ (C) and $\mathrm{[CoCl(NH_3)_5]^{2+}}$ (D) in terms of wavelength of light absorbed is

Identify the correct statements from the following.

statements A–D show pairs of skeletal structures

A. $\mathrm{CH_3CH_2COCH_2CH_3}$ (pentan-3-one) and $\mathrm{CH_3COCH_2CH_2CH_3}$ (pentan-2-one) are metamers B. $\mathrm{CH_3CH_2CH_2{-}CN}$ and $\mathrm{CH_3CH_2CH_2{-}NC}$ are functional isomers C. $\mathrm{CH_3CH_2CH_2CH_2CH_2OH}$ (pentan-1-ol) and $\mathrm{CH_3CH(OH)CH_2CH_2CH_3}$ (pentan-2-ol) are position isomers D. $\mathrm{CH_3CH_2CH_2CH_2NH_2}$ (butan-1-amine) and $\mathrm{CH_3CH_2{-}NH{-}CH_2CH_2CH_3}$ (N-ethylpropan-1-amine) are homologous

Choose the correct answer from the options given below:

Which compound would give 3-methyl-6-oxoheptanal upon ozonolysis?

Identify [A], [B] and [C], respectively in the following reaction sequence:

$$[\mathrm{A}] \xrightarrow[273-278~\mathrm{K}]{\mathrm{NaNO_2,~HCl}} \mathrm{C_6H_5\overset{+}{N_2}Cl^-} \xrightarrow{\mathrm{KI}} [\mathrm{B}] \xrightarrow[\text{Dry ether}]{2\mathrm{Na}} [\mathrm{C}]$$

the intermediate is drawn as benzenediazonium chloride

The least acidic compound, among the following is:

(A) 3-ethoxyphenol (benzene ring with OEt and OH meta to each other); (B) benzenesulfonic acid ($\mathrm{C_6H_5SO_3H}$); (C) butanoic acid ($\mathrm{CH_3CH_2CH_2COOH}$); (D) ethyl propiolate ($\mathrm{EtO_2C{-}C{\equiv}C{-}H}$)

Number of molecules from below which cannot give iodoform reaction is:

Ethanol, Isopropyl alcohol, Bromoacetone, 2−Butanol, 2−Butanone, Butanal, 2−Pentanone, 3−Pentanone, Pentanal and 3−Pentanol.

In the following reactions, which one is NOT correct?

each option shows benzenediazonium chloride ($\mathrm{C_6H_5\overset{+}{N_2}Cl^-}$) converted to a product

Which of the following is the correct structure of L−Fructose?

Given :

$\Delta H^{\ominus}_{\mathrm{sub}}\,[\mathrm{C\,(graphite)}] = 710~\mathrm{kJ~mol^{-1}}$

$\Delta_{\mathrm{C-H}}H^{\ominus} = 414~\mathrm{kJ~mol^{-1}}$

$\Delta_{\mathrm{H-H}}H^{\ominus} = 436~\mathrm{kJ~mol^{-1}}$

$\Delta_{\mathrm{C=C}}H^{\ominus} = 611~\mathrm{kJ~mol^{-1}}$

The $\Delta H_f^{\ominus}$ for $\mathrm{CH_2=CH_2}$ is __________ $\mathrm{kJ~mol^{-1}}$ (nearest integer value)

The number of optical isomers exhibited by the iron complex (A) obtained from the following reaction is __________.

$\mathrm{FeCl_3 + KOH + H_2C_2O_4 \rightarrow A}$

Consider the following reactions

$\underset{\text{Little amount}}{\mathrm{A}} + \mathrm{NaCl} + \mathrm{H_2SO_4} \rightarrow \mathrm{CrO_2Cl_2} + \text{Side Products}$

$\mathrm{CrO_2Cl_2}_{\,\text{(Vapour)}} + \mathrm{NaOH} \rightarrow \mathrm{B} + \mathrm{NaCl} + \mathrm{H_2O}$

$\mathrm{B} + \mathrm{H^+} \rightarrow \mathrm{C} + \mathrm{H_2O}$

The number of terminal 'O' present in the compound 'C' is __________.

0.5 g of an organic compound on combustion gave 1.46 g of $\mathrm{CO_2}$ and 0.9 g of $\mathrm{H_2O}$. The percentage of carbon in the compound is __________. (Nearest integer)

[Given : Molar mass (in g mol$^{-1}$) C : 12, H : 1, O : 16]

During estimation of nitrogen by Dumas' method of compound X (0.42 g)

structure of X — piperazine, a six-membered saturated ring with N–H groups at positions 1 and 4 ($\mathrm{C_4H_{10}N_2}$)

__________ mL of $\mathrm{N_2}$ gas will be liberated at STP. (nearest integer)

(Given molar mass in g mol$^{-1}$ : C : 12, H : 1, N : 14)