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Chemistry

Salicylaldehyde is synthesized from phenol, when reacted with.

Given below are two statements:
Statement – I: High concentration of strong nucleophilic reagent with secondary alkyl halide which do not have bulky substituents will follow \( \mathrm{S_N}{^2} \) mechanism.
Statement – II: A secondary alkyl halide when treated with a large excess of ethanol follows \( \mathrm{S_N}{^1} \) mechanism.
In the light of the above statements, choose the most appropriate from the options given below:

Reduction potential of ion are given below:
\( \mathrm{ClO_4^-} \) \( \mathrm{IO_4^-} \) \( \mathrm{BrO_4^-} \)
\(E^\circ = 1.19 \ \mathrm{V} \) \(E^\circ = 1.65 \ \mathrm{V} \) \(E^\circ = 1.74 \ \mathrm{V} \)
The correct order of their oxidizing power is:

Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R:
Assertion A: \( \mathrm{H_2Te} \) is more acidic than \( \mathrm{H_2S} \).
Reason R: Bond dissociation enthalpy of \( \mathrm{H_2Te} \) is lower than \( \mathrm{H_2S} \).
In the light of the above statements, choose the most appropriate from the options given below:

The solution from the following with highest depression in freezing point/lowest freezing point is:

If a substance ‘A’ dissolves in solution of a mixture of ‘B’ and ‘C’ with their respective number of moles as \( n_A \), \( n_B \) and \( n_C \), Mole fraction of C in the solution is:

Given below are two statements:
Statement-I: Along the period, the chemical reactivity of the element gradually increases from group \( 1 \) to group \( 18 \).
Statement-II: The nature of oxides formed by group \( 1 \) elements is basic while that of group \( 17 \) elements is acidic.
In the light of the above statements, choose the most appropriate from the options given below:

Which among the following purification methods is based on the principle of “Solubility” in two different solvents?

Given below are two statement:
Statement-I: Since Fluorine is more electronegative than nitrogen, the net dipole moment of \( \mathrm{NF_3} \) is greater than \( \mathrm{NH_3} \).
Statement-II: In \( \mathrm{NH_3} \), the orbital dipole due to lone pair and the dipole moment of NH bonds are in opposite direction, but in \( \mathrm{NF_3} \) the orbital dipole due to lone pair and dipole moment of \( \mathrm{N-F} \) bonds are in same direction.
In the light of the above statements, choose the most appropriate from the options given below:

The coordination geometry around the manganese in decacarbonyldimanganese \( (0) \) is:

Alkaline oxidative fusion of \( \mathrm{MnO_2} \) gives “A” which on electrolytic oxidation in alkaline solution produces B. A and B respectively are

The correct stability order of carbocations is:

The products \( A \) and \( B \) formed in the formed reaction scheme are respectively

\(A\) and \(B\) formed in the following reaction are:
\( \mathrm{CrO_2Cl_2} + 4\,\mathrm{NaOH} \rightarrow A + 2\,\mathrm{NaCl} + 2\,\mathrm{H_2O} \)
\( A + 2\,\mathrm{HCl} + 2\,\mathrm{H_2O_2} \rightarrow B + 3\,\mathrm{H_2O} \)

Choose the correct statements about the hydrides of group \( 15 \) elements.
A. The stability of the hydrides decreases in the order \( \mathrm{NH_3} > \mathrm{PH_3} > \mathrm{AsH_3} > \mathrm{SbH_3} > \mathrm{BiH_3} \).
B. The reducing ability of the hydride increases in the order \( \mathrm{NH_3} < \mathrm{PH_3} < \mathrm{AsH_3} < \mathrm{SbH_3} < \mathrm{BiH_3} \).
C. Among the hydrides, \( \mathrm{NH_3} \) is strong reducing agent while \( \mathrm{BiH_3} \) is mild reducing agent.
D. The basicity of the hydrides increases in the order \( \mathrm{NH_3} < \mathrm{PH_3} < \mathrm{AsH_3} < \mathrm{SbH_3} < \mathrm{BiH_3} \).

The molecule / ion with square pyramidal shape is:

IUPAC name of following compound is:

m-chlorobenzaldehyde on treatment with \( 50\% \) \( \mathrm{KOH} \) solution yields

Products \( A \) and \( B \) formed in the following set of reactions are

The orange colour of \( \mathrm{K_2Cr_2O_7} \) and purple colour of \( \mathrm{KMnO_4} \) is due to:

Number of metal ions characterized by flame test among the following is ________.
\( \mathrm{Sr^{2+}} \), \( \mathrm{Ba^{2+}} \), \( \mathrm{Ca^{2+}} \), \( \mathrm{Cu^{2+}} \), \( \mathrm{Zn^{2+}} \), \( \mathrm{Co^{2+}} \), \( \mathrm{Fe^{2+}} \)

The total number of correct statements, regarding the nucleic acids is _______.
A. RNA is regarded as the reserve of genetic information.
B. DNA molecule self-duplicates during cell division.
C. DNA synthesizes proteins in the cell
D. The message for the syntheses of particular proteins is present in DNA
E. Identical DNA strands are transferred to daughter cells.

\( \text{2–chlorobutane} + \mathrm{Cl_2} \rightarrow \mathrm{C_4H_8Cl_2} \) (isomers)
Total number of optically active isomers shown by \( \mathrm{C_4H_8Cl_2} \), obtained in the above reaction is _______.

\( \mathrm{NO_2} \) required for a reaction is produced by decomposition of \( \mathrm{N_2O_5} \) in \( \mathrm{CCl_4} \) as by equation \( 2\mathrm{N_2O_{5(g)}} \rightarrow 4\mathrm{NO_{2(g)}} + \mathrm{O_{2(g)}} \).
The initial concentration of \( \mathrm{N_2O_5} \) is \( 3 \, \mathrm{mol\, L^{-1}} \) and it is \( 2.75 \, \mathrm{mol\, L^{-1}} \) after \( 30 \, \text{minutes} \).
The rate of formation of \( \mathrm{NO_2} \) is \( x \times 10^{-3} \, \mathrm{mol\, L^{-1}\, min^{-1}} \), value of \( x \) is _______. (nearest integer).

Number of geometrical isomers possible for the given structure is/are _______.

Total number of species from the following which can undergo disproportionation reaction is _______.
\( \mathrm{H_2O_2,\ ClO_3^{-},\ P_4,\ Cl_2,\ Ag,\ Cu^{+1},\ F_2,\ NO_2,\ K^{+}} \)

Number of complexes which show optical isomerism among the following is _______.
\( \text{cis-}[\mathrm{Cr(ox)_2Cl_2}]^{3-},\ [\mathrm{Co(en)_3}]^{3+},\ \text{cis-}[\mathrm{Pt(en)_2Cl_2}]^{2+},\ \text{cis-}[\mathrm{Co(en)_2Cl_2}]^{+},\ \text{trans-}[\mathrm{Pt(en)_2Cl_2}]^{2+},\ \text{trans-}[\mathrm{Cr(ox)_2Cl_2}]^{3-} \)

The pH of an aqueous solution containing \( 1\,\mathrm{M} \) benzoic acid \( (\mathrm{p}K_a = 4.20) \) and \( 1\,\mathrm{M} \) sodium benzoate is \( 4.5 \). The volume of benzoic acid solution in \( 300 \, \mathrm{mL} \) of this buffer solution is ______ mL.
(given: \( \log 2 = 0.3 \))

Number of spectral lines obtained in \( \mathrm{He^+} \) spectra, when an electron makes transition form fifth excited state to first excited state will be:

Two reactions are given below:
\( 2\text{Fe(s)} + \dfrac{3}{2}\text{O}_2\text{(g)} \rightarrow \text{Fe}_2\text{O}_3\text{(s)},\ \Delta H^\circ = -822 \,\text{kJ/mol} \)
\( \text{C(s)} + \dfrac{1}{2}\text{O}_2\text{(g)} \rightarrow \text{CO(g)},\ \Delta H^\circ = -110 \,\text{kJ/mol} \)
Then enthalpy change for following reaction \( 3\text{C(s)} + \text{Fe}_2\text{O}_3\text{(s)} \rightarrow 2\text{Fe(s)} + 3\text{CO(g)} \) is _______ \( \text{kJ/mol} \).

JEE Main 2024 30th Jan Evening Shift

Mathematics Physics Chemistry

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\(A\) and \(B\) formed in the following reaction are:
\( \mathrm{CrO_2Cl_2} + 4\,\mathrm{NaOH} \rightarrow A + 2\,\mathrm{NaCl} + 2\,\mathrm{H_2O} \)
\( A + 2\,\mathrm{HCl} + 2\,\mathrm{H_2O_2} \rightarrow B + 3\,\mathrm{H_2O} \)