List of top Questions asked in JEE Main

$A(g) ⇋ 2B(g) + C(g)$
For the given reaction, if the initial pressure is 450 mm Hg and the pressure at time t is 720 mm Hg at a constant temperature T and constant volume V. The fraction of A(g) decomposed under these conditions is $x × 10^{–1}$. The value of x is _____ . (nearest integer)

In alkaline medium, the reduction of permanganate anion involves a gain of _____ electrons.

Let (a+bx+cx²)¹⁰ = $ \sum_{i=0}^{20} $ p_ixⁱ, a,b,c∈N. If p₁=20 and P₂ = 210, then 2(a+b+c) is equal to

The electron in the $n^{th}$ orbit of $Li^{2+}$ is excited to $(n + 1)$ orbit using the radiation of energy $1.47 × 10^{–1}J $ (as shown in the diagrarn). The value of n is ______ .
Given: $R_H = 2.18 × 10^{–18} J$.

The number of incorrect statement/s from the following is ____ .
A. The successive half lives of zero order reactions decreases with time.
B. A substance appearing as reactant in the chemical equation may not affect the rate of reaction.
C. Order and molecularity of a chemical reaction can be a fractional number.
D. The rate constant units of zero and second order reaction are mol L^–1s^–1 and mol^–1 Ls^–1 respectively.

The total number of three-digit numbers, divisible by 3, which can be formed using the digits 1,3,5,8, if repetition of digits is allowed, is

During the reaction of permanganate with thiosulphate, the change in oxidation of manganese occurs by value of 3. Identify which of the below medium will favour the reaction

The number of endothermic process/es from the following is _____ .
A. $I_2 (g) → 2I (g)$
B. $HCl (g) → H(g) + Cl (g)$
C. $H_2O(l) → H_2O (g)$
D. $C(s) + O_2 (g) → CO_2 (g)$
E. Dissolution of ammonium chloride in water.

The difference in the oxidation state of $Xe$ between the oxidised product of $Xe$ formed on complete hydrolysis of $XeF_4$ and $XeF_4$ is _____ .

An aqueous solution of volume 300 cm³ contains 0.63 g of protein. The osmotic pressure of the solution
at 300 K is 1.29 mbar. The molar mass of the protein is ____ g mol^–1.
Given: R = 0.083 L bar K^–1 mol^–1

A proton with a kinetic energy of 2.0 eV moves into a region of uniform magnetic field of magnitude $\dfrac{\pi}{2} \times 10^{-3} \text{T}$. The angle between the direction of magnetic field and velocity of proton is 60°. The pitch of the helical path taken by the proton is \_\_\_\ cm.

The specific conductance of 0.0025 M acetic acid is $5 × 10^{–5} S\ cm^{–1}$ at a certain temperature. The dissociation constant of acetic acid is ___________ $× 10^{–7}.$ (Nearest integer) Consider limiting molar conductivity of $CH_3COOH$ as $400\ S cm^2 mol^{–1}$.

The number of molecules from the following which contain only two lone pair of electrons is _____ .
$H_2O, N_2, CO, XeF_4, NH_3, NO, CO_2, F_2$

Let the determinant of a square matrix A of order $ m $ be $ m - n $, where $ m $ and $ n $ satisfy $ 4m + n = 22 $ and $ 17m + 4n = 93 $. If $ \text{det} (n \, \text{adj}(\text{adj}(mA))) = 3^a 5^b 6^c $, then $ a + b + c $ is equal to:

The weight of a body on the surface of the earth is 100 N. The gravitational force on it when taken at a height, from the surface of earth, equal to one-fourth the radius of the earth is:

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R:
Assertion A: 3.1500 g of hydrated oxalic acid dissolved in water to make 250.0 mL solution will result in 0.1 M oxalic acid solution.
Reason R: Molar mass of hydrated oxalic acid is 126 g mol^–1.
In the light of the above statements, choose the correct answer from the options given below.

Which one of the following elements will remain as liquid inside pure boiling water?

Ferric chloride is applied to stop bleeding because-

The major product P formed in the given reaction is:

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R:
Assertion A: The energy required to form $Mg^{2+}$ from Mg is much higher than that required to produce $Mg^+$
Reason R: $Mg^{2+}$ is small ion and carry more charge than $Mg^{+}$.
In the light of the above statements, choose the correct answer from the options given below.

If the set $\left( Re \left( \frac{z-\bar{z}+z\bar{z}}{2-3z+5\bar{z}}\right) : z ∈ C, Re(z)=3 \right)$ is equal to the interval (α,β), then 24(β-α) is equal to

A simple pendulum with length 100 cm and bob of mass 250 g is executing S.H.M. of amplitude 10cm. The maximum tension in the string is found to be $\frac{x}{40}$ N. The value of x is___.

Incorrect method of preparation for alcohols from the following is:

The decreasing order of hydride affinity for following carbocations is:

Choose the correct answer from the options given below:

The correct order of the number of unpaired electrons in the given complexes is
A. $[Fe(CN)_6]^{3–}$
B. $[FeF_6]^{3–}$
C. $[CoF_6]^{3–}$
D. $[Cr(oxalate)_3]^{3–}$
E. $[Ni(CO)_4]$
Choose the correct answer from the options given below: