JEE Main 2024 Apr 4 Shift 1 — Chemistry

The Molarity (M) of an aqueous solution containing 5.85 g of NaCl in 500 mL water is : (Given : Molar Mass Na : 23 and Cl : 35.5 gmol$^{-1}$)

Which one of the following molecules has maximum dipole moment ?

What will be the decreasing order of basic strength of the following conjugate bases ?

$\mathrm{^-OH,\ R\bar{O},\ CH_3CO\bar{O},\ \bar{Cl}}$

One of the commonly used electrode is calomel electrode. Under which of the following categories, calomel electrode comes ?

What pressure (bar) of $\mathrm{H_2}$ would be required to make emf of hydrogen electrode zero in pure water at 25°C ?

The correct order of first ionization enthalpy values of the following elements is : (A) O (B) N (C) Be (D) F (E) B Choose the correct answer from the options given below :

Number of elements from the following that CANNOT form compounds with valencies which match with their respective group valencies is _________. B, C, N, S, O, F, P, Al, Si

Number of molecules/ions from the following in which the central atom is involved in $\mathrm{sp^3}$ hybridization is ________.

$\mathrm{NO_3^-,\ BCl_3,\ ClO_2^-,\ ClO_3}$

The element which shows only one oxidation state other than its elemental form is :

The correct sequence of ligands in the order of decreasing field strength is :

Number of complexes from the following with even number of unpaired "d" electrons is ________.

$\mathrm{[V(H_2O)_6]^{3+}, [Cr(H_2O)_6]^{2+}, [Fe(H_2O)_6]^{3+}, [Ni(H_2O)_6]^{3+}, [Cu(H_2O)_6]^{2+}}$

[Given atomic numbers : V = 23, Cr = 24, Fe = 26, Ni = 28 Cu = 29]

In the precipitation of the iron group (III) in qualitative analysis, ammonium chloride is added before adding ammonium hydroxide to :

Which of the following nitrogen containing compound does not give Lassaigne's test ?

Match List I with List II :

List-I shows four curved-arrow mechanism steps: (A) aniline resonance — the $\mathrm{NH_2}$ lone pair delocalises into the benzene ring giving the $\mathrm{{}^+NH_2}$= iminium resonance structure with a ring carbanion; (B) cyclohexene $+ \mathrm{H^+} \rightarrow$ cyclohexyl carbocation; (C) cyclohexene $+ \mathrm{\bar{C}N} \rightarrow$ cyclohexyl carbanion bearing a CN group; (D) nitrobenzene resonance — the $\mathrm{-NO_2}$ group withdraws ring electrons giving a ring carbocation resonance structure.

List - I (Mechanism steps)	List - II (Effect)
(A) aniline lone-pair delocalisation into ring	(I) $-$ E effect
(B) cyclohexene $+ \mathrm{H^+} \rightarrow$ carbocation	(II) $-$ R effect
(C) cyclohexene $+ \mathrm{\bar{C}N} \rightarrow$ carbanion with CN	(III) $+$ E effect
(D) nitrobenzene ring-electron withdrawal by $\mathrm{-NO_2}$	(IV) $+$ R effect

Choose the correct answer from the options given below :

Which among the following is incorrect statement ?

compound (A) is 1-bromo-4-(2-bromoethyl)benzene — a benzene ring with Br at the para position and a $\mathrm{-CH_2CH_2Br}$ side chain

$$\mathrm{(A) \xrightarrow{NaOH_{(alc)}} \ (B) \ \xrightarrow[Ether]{HBr} \ (C)}$$

Identify (B) and (C) and how are (A) and (C) related ?

Identify the correct set of reagents or reaction conditions 'X' and 'Y' in the following set of transformation.

$$\mathrm{CH_3-CH_2-CH_2-Br \xrightarrow{'X'} Product \xrightarrow{'Y'} \underset{\underset{\mathrm{Br}}{|}}{CH_3-CH}-CH_3}$$

Given below are two statements :

Statements I : Acidity of α-hydrogens of aldehydes and ketones is responsible for Aldol reaction.

Statement II : Reaction between benzaldehyde and ethanal will NOT give Cross - Aldol product.

In the light of the above statements, choose the most appropriate answer from the options given below :

Identify the product in the following reaction :

3-acetylbenzaldehyde — a benzene ring bearing a $\mathrm{-CHO}$ group and a $\mathrm{-COCH_3}$ group at meta positions

$$\xrightarrow[\mathrm{HCl}]{\mathrm{Zn-Hg}} \text{Product}$$

Which of the following is the correct structure of L-Glucose ?

The de-Broglie's wavelength of an electron in the 4$^{th}$ orbit is ________ $\pi a_0$. ($a_0$ = Bohr's radius)

Number of molecules/species from the following having one unpaired electron is ________.

$\mathrm{O_2,\ O_2^{-1},\ NO,\ CN^{-1},\ O_2^{2-}}$

The enthalpy of formation of ethane ($\mathrm{C_2H_6}$) from ethylene by addition of hydrogen where the bond-energies of $\mathrm{C-H}$, $\mathrm{C-C}$, $\mathrm{C{=}C}$, $\mathrm{H-H}$ are 414 kJ, 347 kJ, 615 kJ and 435 kJ respectively is $-$________ kJ

2.5 g of a non-volatile, non-electrolyte is dissolved in 100 g of water at 25°C. The solution showed a boiling point elevation by 2°C. Assuming the solute concentration is negligible with respect to the solvent concentration, the vapor pressure of the resulting aqueous solution is ________ mm of Hg (nearest integer)

[Given : Molal boiling point elevation constant of water ($K_b$) = 0.52 K. kg mol$^{-1}$, 1 atm pressure = 760 mm of Hg, molar mass of water = 18 g mol$^{-1}$]

Consider the following transformation involving first order elementary reaction in each step at constant temperature as shown below.

$$\mathrm{A + B \underset{Step\ 3}{\overset{Step\ 1}{\rightleftharpoons}} C \xrightarrow{Step\ 2} P}$$

Some details of the above reactions are listed below.

Step	Rate constant (sec$^{-1}$)	Activation energy (kJ mol$^{-1}$)
1	$k_1$	300
2	$k_2$	200
3	$k_3$	$Ea_3$

If the overall rate constant of the above transformation (k) is given as $k = \dfrac{k_1 k_2}{k_3}$ and the overall activation energy ($E_a$) is 400 kJ mol$^{-1}$, then the value of $Ea_3$ is ________ kJ mol$^{-1}$ (nearest integer)

Consider the following reaction

$$\mathrm{MnO_2 + KOH + O_2 \rightarrow A + H_2O.}$$

Product 'A' in neutral or acidic medium disproportionate to give products 'B' and 'C' along with water. The sum of spin-only magnetic moment values of B and C is ________ BM. (nearest integer) (Given atomic number of Mn is 25)

Only 2 mL of $\mathrm{KMnO_4}$ solution of unknown molarity is required to reach the end point of a titration of 20 mL of oxalic acid (2 M) in acidic medium. The molarity of $\mathrm{KMnO_4}$ solution should be ________ M.

The number of different chain isomers for $\mathrm{C_7H_{16}}$ is ________.

The number of the correct reaction(s) among the following is ________.

four reaction schemes

(A) benzene $+$ benzoyl chloride ($\mathrm{C_6H_5COCl}$) $\xrightarrow{\text{Anhyd.}\mathrm{AlCl_3}}$ diphenylmethane ($\mathrm{C_6H_5CH_2C_6H_5}$)

(B) benzoyl chloride ($\mathrm{C_6H_5COCl}$) $\xrightarrow[\mathrm{Pd-BaSO_4}]{\mathrm{H_2}}$ benzoic acid ($\mathrm{C_6H_5COOH}$)

(C) benzene $\xrightarrow[\text{Anhyd.}\mathrm{AlCl_3/CuCl}]{\mathrm{CO, HCl}}$ benzaldehyde ($\mathrm{C_6H_5CHO}$)

(D) benzamide ($\mathrm{C_6H_5CONH_2}$) $\xrightarrow[\Delta]{\mathrm{H_3O^+}}$ aniline ($\mathrm{C_6H_5NH_2}$)

X g of ethylamine is subjected to reaction with $\mathrm{NaNO_2/HCl}$ followed by water; evolved dinitrogen gas which occupied 2.24 L volume at STP. X is ________ $\times 10^{-1}$ g.