JEE Main 2024 Apr 9 Shift 1 — Chemistry

Compare the energies of following sets of quantum numbers for multielectron system. (A) $n = 4, l = 1$ (B) $n = 4, l = 2$ (C) $n = 3, l = 1$ (D) $n = 3, l = 2$ (E) $n = 4, l = 0$ Choose the correct answer from the options given below :

In which one of the following pairs the central atoms exhibit $\mathrm{sp^2}$ hybridization ?

0.05M $\mathrm{CuSO_4}$ when treated with 0.01M $\mathrm{K_2Cr_2O_7}$ gives green colour solution of $\mathrm{Cu_2Cr_2O_7}$. The two solutions are separated as shown below : [SPM : Semi Permeable Membrane]

two compartments separated by a semi permeable membrane; Side X contains $\mathrm{K_2Cr_2O_7}$ solution, Side Y contains $\mathrm{CuSO_4}$ solution

Due to osmosis :

The molar conductivity for electrolytes A and B are plotted against $\mathrm{C^{1/2}}$ as shown below. Electrolytes A and B respectively are :

plot of $\Lambda_m\ (\mathrm{S\ cm^2\ mol^{-1}})$ vs $\mathrm{C^{1/2}\ (mol\ L^{-1})^{1/2}}$; curve A falls steeply from about 400 at very low concentration, curve B decreases slowly and nearly linearly from about 200

Given below are two statements : Statement (I) : The oxidation state of an element in a particular compound is the charge acquired by its atom on the basis of electron gain enthalpy consideration from other atoms in the molecule. Statement (II) : $\mathrm{p\pi - p\pi}$ bond formation is more prevalent in second period elements over other periods. In the light of the above statements, choose the most appropriate answer from the options given below :

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : Both rhombic and monoclinic sulphur exist as $\mathrm{S_8}$ while oxygen exists as $\mathrm{O_2}$. Reason (R) : Oxygen forms $\mathrm{p\pi - p\pi}$ multiple bonds with itself and other elements having small size and high electronegativity like C, N, which is not possible for sulphur. In the light of the above statements, choose the most appropriate answer from the options given below :

The $\mathrm{F^-}$ ions make the enamel on teeth much harder by converting hydroxyapatite (the enamel on the surface of teeth) into much harder fluoroapatite having the formula.

The electronic configuration of Cu(II) is $\mathrm{3d^9}$ whereas that of Cu(I) is $\mathrm{3d^{10}}$. Which of the following is correct ?

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : The total number of geometrical isomers shown by $\mathrm{[Co(en)_2Cl_2]^+}$ complex ion is three. Reason (R) : $\mathrm{[Co(en)_2Cl_2]^+}$ complex ion has an octahedral geometry. In the light of the above statements, choose the most appropriate answer from the options given below :

Methods used for purification of organic compounds are based on :

Relative stability of the contributing structures is :

$$\mathrm{CH_2{=}CH{-}CH{=}O\ \,(I)\ \longleftrightarrow\ \overset{+}{C}H_2{-}CH{=}CH{-}\overset{-}{O}\ \,(II)\ \longleftrightarrow\ \overset{-}{C}H_2{-}CH{=}CH{-}\overset{+}{O}\ \,(III)}$$

(Resonance structures of prop-2-enal: (I) neutral structure with $\mathrm{C{=}O}$; (II) positive charge on terminal $\mathrm{CH_2}$ carbon and negative charge on oxygen; (III) negative charge on terminal $\mathrm{CH_2}$ carbon and positive charge on oxygen)

benzene + succinic anhydride $\xrightarrow{\mathrm{AlCl_3}}$ A $\xrightarrow[\mathrm{HCl}

{\mathrm{Zn{-}Hg}}$B$\xrightarrow{\text{Conc. } \mathrm{H_2SO_4}}$ C]*

What is the structure of C ?

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : $\mathrm{S_N2}$ reaction of $\mathrm{C_6H_5CH_2Br}$ occurs more readily than the $\mathrm{S_N2}$ reaction of $\mathrm{CH_3CH_2Br}$. Reason (R) : The partially bonded unhybridized p-orbital that develops in the trigonal bipyramidal transition state is stabilized by conjugation with the phenyl ring. In the light of the above statements, choose the most appropriate answer from the options given below :

In the following sequence of reaction, the major products B and C respectively are :

1-bromo-3-chlorocyclobutane (Cl and Br on opposite corners of a cyclobutane ring) $\xrightarrow{\mathrm{Na/Et_2O}}$ A ; A $\xrightarrow[\mathrm{(ii)\ D_2O}

{\mathrm{(i)\ Mg/Et_2O}}$B ; A$\xrightarrow{\mathrm{CoF_2}}$ C]*

Identify major product "X" formed in the following reaction :

$$\mathrm{C_6H_6 \xrightarrow[\text{Anhydrous } AlCl_3/CuCl]{CO,\ HCl} X\ (Major\ Product)}$$

Identify the product A and product B in the following set of reactions.

$$\mathrm{CH_3{-}CH{=}CH_2 \xrightarrow{H_2O,\ H^+} major\ Product\ A}$$ $$\mathrm{CH_3{-}CH{=}CH_2 \xrightarrow[H_2O,\ H_2O_2,\ \bar{O}H]{(BH_3)_2} major\ Product\ B}$$

For the given compounds, the correct order of increasing $\mathrm{pK_a}$ value : (A)

phenol

(B)

4-nitrophenol ($\mathrm{O_2N}$ para to $\mathrm{OH}$)

(C)

3-methoxyphenol ($\mathrm{OCH_3}$ meta to $\mathrm{OH}$)

(D)

3-nitrophenol ($\mathrm{NO_2}$ meta to $\mathrm{OH}$)

(E)

4-methoxyphenol ($\mathrm{OCH_3}$ para to $\mathrm{OH}$)

Choose the correct answer from the options given below :

Correct order of basic strength of Pyrrole, Pyridine and Piperidine is :

structures of pyrrole (five-membered aromatic ring with N-H), pyridine (six-membered aromatic ring with N) and piperidine (saturated six-membered ring with N-H)

On reaction of Lead Sulphide with dilute nitric acid which of the following is not formed ?

Identify the incorrect statements regarding primary standard of titrimetric analysis. (A) It should be purely available in dry form. (B) It should not undergo chemical change in air. (C) It should be hygroscopic and should react with another chemical instantaneously and stoichiometrically. (D) It should be readily soluble in water. (E) $\mathrm{KMnO_4}$ & NaOH can be used as primary standard. Choose the correct answer from the options given below :

Molarity (M) of an aqueous solution containing $x$ g of anhyd. $\mathrm{CuSO_4}$ in 500 mL solution at 32 °C is $2 \times 10^{-1}$ M. Its molality will be ________ $\times 10^{-3}$ m. (nearest integer). [Given density of the solution = 1.25 g/mL]

The total number of species from the following in which one unpaired electron is present, is ________. $$\mathrm{N_2,\ O_2,\ C_2^-,\ O_2^-,\ O_2^{2-},\ H_2^+,\ CN^-,\ He_2^+}$$

The heat of solution of anhydrous $\mathrm{CuSO_4}$ and $\mathrm{CuSO_4 \cdot 5H_2O}$ are $-70\ \mathrm{kJ\ mol^{-1}}$ and $+12\ \mathrm{kJ\ mol^{-1}}$ respectively. The heat of hydration of $\mathrm{CuSO_4}$ to $\mathrm{CuSO_4 \cdot 5H_2O}$ is $-x$ kJ. The value of $x$ is ________. (nearest integer).

When equal volume of 1M HCl and 1M $\mathrm{H_2SO_4}$ are separately neutralised by excess volume of 1M NaOH solution, $x$ and $y$ kJ of heat is liberated respectively. The value of $y/x$ is ________.

The standard reduction potentials at 298 K for the following half cells are given below : $$\mathrm{Cr_2O_7^{2-} + 14H^+ + 6e^- \rightarrow 2Cr^{3+} + 7H_2O},\quad E^\circ = 1.33\ \mathrm{V}$$ $$\mathrm{Fe^{3+}(aq) + 3e^- \rightarrow Fe},\quad E^\circ = -0.04\ \mathrm{V}$$ $$\mathrm{Ni^{2+}(aq) + 2e^- \rightarrow Ni},\quad E^\circ = -0.25\ \mathrm{V}$$ $$\mathrm{Ag^{+}(aq) + e^- \rightarrow Ag},\quad E^\circ = 0.80\ \mathrm{V}$$ $$\mathrm{Au^{3+}(aq) + 3e^- \rightarrow Au},\quad E^\circ = 1.40\ \mathrm{V}$$ Consider the given electrochemical reactions, The number of metal(s) which will be oxidized by $\mathrm{Cr_2O_7^{2-}}$ in aqueous solution is ________.

Given below are two statements : Statement I : The rate law for the reaction $\mathrm{A + B \rightarrow C}$ is rate $(r) = k[\mathrm{A}]^2[\mathrm{B}]$. When the concentration of both A and B is doubled, the reaction rate is increased "$x$" times. Statement II :

linear plot of concentration of R versus time, starting at $[\mathrm{R_0}

$and decreasing with slope$= -K$]* The figure is showing "the variation in concentration against time plot" for a "$y$" order reaction. The Value of $x + y$ is ________.

Number of colourless lanthanoid ions among the following is ________. $$\mathrm{Eu^{3+},\ Lu^{3+},\ Nd^{3+},\ La^{3+},\ Sm^{3+}}$$

Number of ambidentate ligands among the following is ________. $$\mathrm{NO_2^-,\ SCN^-,\ C_2O_4^{2-},\ NH_3,\ CN^-,\ SO_4^{2-},\ H_2O}.$$

How many compounds among the following compounds show inductive, mesomeric as well as hyperconjugation effects ?

eight structures — anisole ($\mathrm{C_6H_5OCH_3}$); $\mathrm{(CH_3)_2CH{-}CH{=}CH{-}CO{-}CH_3}$ (5-methylhex-3-en-2-one); benzene; chlorocyclohexane; 1-isopropyl-2-nitrobenzene; 1-(but-3-en-2-yl)-2-nitrobenzene; 1,3-dimethylbenzene (m-xylene); 1-acetyl-2-methylcyclohexene ($\mathrm{COCH_3}$ and $\mathrm{CH_3}$ on the double-bond carbons of cyclohexene)

Total number of essential amino acid among the given list of amino acids is ________. Arginine, Phenylalanine, Aspartic acid, Cysteine, Histidine, Valine, Proline