JEE Main 2025 Apr 7 Shift 1 — Chemistry

At the sea level, the dry air mass percentage composition is given as nitrogen gas: 70.0, oxygen gas: 27.0 and argon gas: 3.0. If total pressure is 1.15 atm, then calculate the ratio of following respectively:

(i) partial pressure of nitrogen gas to partial pressure of oxygen gas

(ii) partial pressure of oxygen gas to partial pressure of argon gas

(Given: Molar mass of N, O and Ar are 14, 16 and 40 g mol$^{-1}$ respectively.)

visible spectrum strip labelled with wavelength $\lambda$ (nanometers) from 400 to 750 nm, showing violet through red

Which of the following statements are correct, if the threshold frequency of caesium is $5.16 \times 10^{14}$ Hz?

A. When Cs is placed inside a vacuum chamber with an ammeter connected to it and yellow light is focused on Cs, the ammeter shows the presence of current. B. When the brightness of the yellow light is dimmed, the value of the current in the ammeter is reduced. C. When a red light is used instead of the yellow light, the current produced is higher with respect to the yellow light. D. When a blue light is used, the ammeter shows the formation of current. E. When a white light is used, the ammeter shows formation of current.

Choose the correct answer from the options given below:

Total enthalpy change for freezing of 1 mol of water at 10°C to ice at $-10$°C is __________

(Given: $\Delta_{\text{fus}}H = x$ kJ/mol

$C_p[\mathrm{H_2O(l)}] = y\ \mathrm{J\ mol^{-1}\ K^{-1}}$

$C_p[\mathrm{H_2O(s)}] = z\ \mathrm{J\ mol^{-1}\ K^{-1}}$

An aqueous solution of HCl with pH 1.0 is diluted by adding equal volume of water (ignoring dissociation of water). The pH of HCl solution would

(Given log 2 = 0.30)

Given below are two statements:

Statement I: Mohr's salt is composed of only three types of ions-ferrous, ammonium and sulfate.

Statement II: If the molar conductance at infinite dilution for ferrous, ammonium and sulfate ions are $x_1$, $x_2$ and $x_3$ S cm$^2$ mol$^{-1}$, respectively then the molar conductance for Mohr's salt solution at infinite dilution would be given by $x_1 + x_2 + 2x_3$

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

Reaction $\mathrm{A(g) \rightarrow 2B(g) + C(g)}$ is a first order reaction. It was started with pure A

t/min	Pressure of system at time t/mm Hg
10	160
$\infty$	240

Which of the following option is incorrect?

A person's wound was exposed to some bacteria and then bacterial growth started to happen at the same place. The wound was later treated with some antibacterial medicine and the rate of bacterial decay (r) was found to be proportional with the square of the existing number of bacteria at any instance. Which of the following set of graphs correctly represents the 'before' and 'after' situation of the application of the medicine?

[Given: N = No. of bacteria, t = time, bacterial growth follows 1$^{st}$ order kinetics.]

Match the LIST-I with LIST-II

LIST-I (Molecule / ion)	LIST-II (Bond pair : lone pair (on the central atom))
A. $\mathrm{ICl_2^-}$	I. 4 : 2
B. $\mathrm{H_2O}$	II. 4 : 1
C. $\mathrm{SO_2}$	III. 2 : 3
D. $\mathrm{XeF_4}$	IV. 2 : 2

Choose the correct answer from the options given below:

The number of valence electrons present in the metal among Cr, Co, Fe and Ni which has the lowest enthalpy of atomisation is

The group 14 elements A and B have the first ionisation enthalpy values of 708 and 715 kJ mol$^{-1}$ respectively. The above values are lowest among their group members. The nature of their ions $\mathrm{A^{2+}}$ and $\mathrm{B^{4+}}$ respectively is

The first transition series metal 'M' has the highest enthalpy of atomisation in its series. One of its aquated ion ($\mathrm{M^{n+}}$) exists in green colour. The nature of the oxide formed by the above $\mathrm{M^{n+}}$ ion is:

An octahedral complex having molecular composition $\mathrm{Co.5NH_3.Cl.SO_4}$ has two isomers A and B. The solution of A gives a white precipitate with $\mathrm{AgNO_3}$ solution and the solution of B gives white precipitate with $\mathrm{BaCl_2}$ solution. The type of isomerism exhibited by the complex is,

When a salt is treated with sodium hydroxide solution it gives gas X. On passing gas X through reagent Y a brown coloured precipitate is formed. X and Y respectively, are

Given below are two statements:

Statement I: Dimethyl ether is completely soluble in water. However, diethyl ether is soluble in water to a very small extent.

Statement II: Sodium metal can be used to dry diethyl ether and not ethyl alcohol.

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

Which of the following is the correct IUPAC name of given organic compound (X)?

alkene with $\mathrm{H_3C}$ and H on one doubly-bonded carbon, and $\mathrm{CH_3}$ and $\mathrm{CH_2Br}$ on the other; i.e. $\mathrm{CH_3CH{=}C(CH_3)CH_2Br}$, labelled (X)

The reactions which cannot be applied to prepare an alkene by elimination, are

A.

1-bromo-2-methylcyclohexane

$\xrightarrow{\text{NaOEt}}$

B. $\mathrm{CH_3{-}CH_2{-}\underset{\underset{\mathrm{Br}}{|}}{CH}{-}CH_3} \xrightarrow{\text{KOH (aq)}}$

C. $\mathrm{(CH_3)_3C{-}Br} \xrightarrow{\text{NaOMe}}$

D.

phenol

$\xrightarrow[\mathrm{H_2SO_4}]{\mathrm{Na_2Cr_2O_7}}$

E. $\mathrm{(CH_3)_3C{-}OH} \xrightarrow[573\ \mathrm{K}]{\text{Cu}}$

Choose the correct answer from the options given below:

Given below are two statements:

Statement I: Ozonolysis followed by treatment with Zn, $\mathrm{H_2O}$ of cis-2-butene gives ethanal.

Statement II: The product obtained by ozonolysis followed by treatment with Zn, $\mathrm{H_2O}$ of 3, 6-dimethyloct-4-ene has no chiral carbon atom.

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

Which of the following compounds is least likely to give effervescence of $\mathrm{CO_2}$ in presence of aq. $\mathrm{NaHCO_3}$ ?

Which of the following amine (s) show (s) positive carbylamine test?

A.

aniline — $\mathrm{C_6H_5NH_2}$

B. $\mathrm{(CH_3)_2NH}$ C. $\mathrm{CH_3NH_2}$ D. $\mathrm{(CH_3)_3N}$ E.

N-methylaniline — $\mathrm{C_6H_5NH(CH_3)}$

Choose the correct answer from the options given below:

Given below are two statements:

Statement I: D-(+)-glucose + D-(+) fructose $\xrightarrow{-\mathrm{H_2O}}$ Sucrose

sucrose $\xrightarrow{\text{hydrolysis}}$ D-(+) glucose + D-(+) fructose

Statement II: Invert sugar is formed during sucrose hydrolysis

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

1 Faraday electricity was passed through $\mathrm{Cu^{2+}}$ (1.5 M, 1 L) /Cu and 0.1 Faraday was passed through $\mathrm{Ag^{+}}$ (0.2 M, 1 L)/Ag electrolytic cells. After this the two cells were connected as shown below to make an electrochemical cell. The emf of the cell thus formed at 298 K is __________ mV (nearest integer)

electrochemical cell — Cu electrode in $\mathrm{Cu^{2+}(aq)}$ and Ag electrode in $\mathrm{Ag^{+}(aq)}$ connected through a salt bridge and a voltmeter

Given : $E^{\circ}_{\mathrm{Cu^{2+}/Cu}} = 0.34$ V

$E^{\circ}_{\mathrm{Ag^{+}/Ag}} = 0.8$ V

$\frac{2.303RT}{F} = 0.06$ V

The percentage dissociation of a salt ($\mathrm{MX_3}$) solution at given temperature (van't Hoff factor i = 2) is ___________ %(Nearest integer)

The number of paramagnetic complexes among $\mathrm{[FeF_6]^{3-}}$, $\mathrm{[Fe(CN)_6]^{3-}}$, $\mathrm{[Mn(CN)_6]^{3-}}$, $\mathrm{[Co(C_2O_4)_3]^{3-}}$, $\mathrm{[MnCl_6]^{3-}}$, and $\mathrm{[CoF_6]^{3-}}$, which involved $\mathrm{d^2sp^3}$ hybridization is ___________

An organic compound weighing 500 mg, produced 220 mg of $\mathrm{CO_2}$, on complete combustion. The percentage composition of carbon in the compound is ________%. (nearest integer)

(Given molar mass in g mol$^{-1}$ of C:12, O:16)

Thyroxine, the hormone has given below structure

thyroxine structure — HO-substituted benzene ring bearing two iodine atoms, linked via an ether oxygen to a second benzene ring bearing two iodine atoms, which carries a $\mathrm{CH_2CH(NH_2)COOH}$ side chain

The percentage of iodine in thyroxine is ______%. (nearest integer)

(Given molar mass in g mol$^{-1}$ C:12, H:1, O:16, N:14, I:127)