List of top Questions asked in JEE Main- 2023

The standard electrode potential \((\frac{M^{3+}}{M^{2+}})\) for V, Cr, Mn & Co are –0.26 V, –0.41 V, +1.57 V and +1.97 V, respectively. The metal ions which can liberate H₂ from a dilute acid are

Match List I with List II

List-I	Reaction	List-II	Reagents
(A)	Hoffmann Degradation	(I)	Conc.KOH,\(\triangle\)
(B)	Clemenson reduction	(II)	CHCl₃, NaOH/H₃O⁺
(C)	Cannizaro reaction	(III)	Br₂, NaOH
(D)	Reimer-Tiemann Reaction	(IV)	Zn-Hg/HCl

Choose the correct answer from the option given below:

The magnetic behavior of Li₂O, Na₂O₂ and KO₂, respectively, are

The bond dissociation energy is highest for

The shortest wavelength of hydrogen atom in Lyman series is λ. The longest wavelength in Balmer series of He⁺ is

The reaction representing the Mond process for metal refining is _________.

Chiral complex from the following is

Compound that will give positive Lassaigne’s test for both nitrogen and halogen is

Which of the following salt solutions would coagulate the colloid solution formed when FeCl₃ is added to NaOH solution, at the fastest rate?

The increasing order of pKa for the following phenols is
(A) 2,4-Dinitrophenol
(B) 4-Nitrophenol
(C) 2,4,5-Trimethylphenol
(D) Phenol
(E) 3-Chlorophenol
Choose the correct answer from the option given below :

Correct statement about smog is

For 1 mol of gas, the plot of pV vs. p is shown below. p is the pressure and V is the volume of the gas. What is the value of compressibility factor at point A?

Solid Lead nitrate is dissolved in 1 litre of water. The solution was found to boil at \(100.15\degree C\). When 0.2 mol of NaCl is added to the resulting solution, it was observed that the solution froze at \(–0.8\degree C\). The solubility product of PbCl₂ formed is ________ \(\times 10^{–6}\) at 298 K. (Nearest integer) Given: \(Kb = 0.5 K \text{ kg mol}^{–1}\) and \(Kf = 1.8 K \text{ kg mol}^{–1}\).
Assume molality to be equal to molarity in all cases.

The number of molecules or ions from the following, which do not have odd number of electrons are ______.
(A) NO₂
(B) ICI₄^-
(C) BrF₃
(D) CIO₂
(E) NO₂²⁺
(F) NO

Following figure shows dependence of molar conductance of two electrolytes on concentration. Λ^o _m is the limiting molar conductivity. The number of incorrect statement(s) from the following is ________

(A) \(\Lambda \text{o m}\) for electrolyte A is obtained by extrapolation.
(B) For electrolyte B, \(\Lambda \text{m}\) vs \(\sqrt c\) graph is a straight line with intercept equal to o \(\Lambda \text{m}\)
(C) At infinite dilution, the value of degree of dissociation approaches zero for electrolyte B.
(D) Λo m for any electrolyte A or B can be calculated using \(\lambda0\) for individual ions.

For certain chemical reaction X 🡢 Y, the rate of formation of product is plotted against the time as shown in the figure. The number of correct statement/s from the following is______.
(A) Over all order of this reaction is one
(B) Order of this reaction can't be determined
(C) In region I and III, the reaction is of first and zero order respectively
(D) In region-II, the reaction is of first order
(E) In region-II, the order of reaction is in the range of 0.1 to 0.9.

The sum of bridging carbonyls in W(CO)₆ and Mn₂(CO)₁₀ is_____.

Following chromatogram was developed by adsorption of compound 'A' on a 6 cm TLC glass plate. Retardation factor of the compound 'A' is_____ \(\times 10^{–1}\).

17 mg of a hydrocarbon (M.F. C₁₀H₁₆) takes up 8.40 mL of the H₂ gas measured at \(0\degree C\) and 760 mm of Hg. Ozonolysis of the same hydrocarbon yields

The number of double bond/s present in the hydrocarbon is_______.

Let [x] denote the greatest integer ≤ x. Consider the function \(f(x)=max \{x^2,1+[x] \}\). Then the value of the integral \(∫_0^2 f(x)dx\) is

Let the tangents at the points A(4, –11) and B(8, –5) on the circle \(x^2+y^2-3x+10y-15=0\), intersect at the point C. Then the radius of the circle, whose centre is C and the line joining A and B is its tangent, is equal to

Let
\(A=\{(x,y) ∈R^2:y≥0,2x≤y≤\sqrt{4-(x-1)^2} \}\)
and
\(B=\{(x,y) ∈R\times R:0≤y≤min \{2x,\sqrt{4-(x-1)^2}\}\}\)
Then the ratio of the area of A to the area of B is

Let α and β be real numbers. Consider a \(3 \times 3\) matrix A such that \(A^2 = 3A + \alpha I\). If \(A^4 = 21A + \beta I\), then

Let \(f(\theta)=3[sin^4(\frac{3\pi}{2}-\theta)+sin^4(3\pi+θ)]-2(1-sin^22\theta)\) and \(S=\{\theta∈[0,\pi]:f'(\theta)=-\frac{\sqrt3}{2}\}\). If \(4\beta \sum_{\theta∈S}\theta\), then \(f(\beta)\) is equal to

Consider the following system of equations
\(\alpha x + 2y + z = 1\)
\(2\alpha x + 3y + z = 1\)
\(3x + \alpha y + 2z = b\)
For some \(\alpha,\beta∈R\) then which of the following is NOT correct?