List of top Chemistry Questions asked in JEE Main

The wavelength of an electron and a neutron will become equal when the velocity of the electron is x times the velocity of neutron. The value of x is ______. (Nearest integer)
(Mass of electron is 9.1 × 10–31 kg and mass of neutron is 1.6 × 10–27 kg)
When 5 moles of He gas expand isothermally and reversibly at 300 K from 10 litre to 20 litre, the magnitude of the maximum work obtained is _____ J. [nearest integer] (Given : R = 8.3 J K–1 mol–1 and log 2 = 0.3010)
2NO + 2H2 → N2 + 2H2O
The above reaction has been studied at 800 °C. The related data is given in the table below.
The order of the reaction with respect to NO is ___.
A 2.0 g sample containing MnO2 is treated with HCl liberating Cl2. The Cl2 gas is passed into a solution of KI and 60.0 mL of 0.1 M Na2S2O3 is required to titrate the liberated iodine. The percentage of MnO2 in the sample is ______. (Nearest integer)
[Atomic masses (in u) Mn = 55; Cl = 35.5; O = 16, I = 127, Na = 23, K = 39, S = 32]
Ka1, Ka2 and Ka3 are the respective ionization constants for the following reactions (a),(b), and (c).
(a) H2C2O4⇌H++HC2O4−
(b) HC2O4−⇌H++HC2O42−
(c) H2C2O4⇌2H++C2O42−
The relationship between Ka1,Ka2 and Ka3 is given as
‘x’ g of molecular oxygen (O2) is mixed with 200 g of neon (Ne). The total pressure of the non-reactive mixture of O2 and Ne in the cylinder is 25 bar. The partial pressure of Ne is 20 bar at the same temperature and volume. The value of ‘x’ is ___.
[Given : Molar mass of O2 = 32 g mol–1 and Molar mass of Ne = 20 g mol–1]
While performing a thermodynamics experiment, a student made the following observations.
HCl + NaOH \(\rightarrow\) NaCl + H2O; ΔH = – 57.3 kJ mol–1
CH3COOH + NaOH \(\rightarrow\) CH3COONa + H2O; ΔH = –55.3 kJ mol–1
The enthalpy of ionization of CH3COOH, as calculated by the student, is ______ kJ mol–1. [nearest integer]
At 310 K, the solubility of CaF2 in water is 2.34 ×10–3 g/100 mL. The solubility product of CaF2 is _____ × 10–8 (mol/L)3.
(Given molar mass : CaF2 = 78 g mol–1).
When 800 mL of 0.5 M nitric acid is heated in a beaker, its volume is reduced to half and 11.5 g of nitric acid is evaporated. The molarity of the remaining nitric acid solution is \(x × 10^{–2} M\). (Nearest integer)
(Molar mass of nitric acid is 63 g mol–1)
A flask is filled with equal moles of A and B. The half lives of A and B are 100 s and 50 s respectively and are independent of the initial concentration. The time required for the concentration of A to be four times that of B is ________s.
(Given : In 2 = 0.693)
Number of electron deficient molecules among the following
\(PH_3, B_2H_6, CCl_4, NH_3, LiH \) and \(BCl_3\) is
A \(100\) \(mL\) solution of \(CH_3CH_2MgBr\) on treatment with methanol produces \(2.24\) \(mL\) of a gas at STP. The weight of gas produced is_____ mg. [nearest integer]
Consider the reaction
\(4\text{HNO}_3(\text{l}) + 3\text{KCl}(\text{s}) \rightarrow \text{Cl}_2(\text{g}) + \text{NOCl}(\text{g}) + 2\text{H}_2\text{O}(\text{g}) + 3\text{KNO}_3(\text{s})\)
The amount of HNO3 required to produce 110.0 g of KNO3 is
(Given : Atomic masses of H, O, N and K are 1, 16, 14 and 39 respectively.)
Polar stratospheric clouds facilitate the formation of:

Using the rules for significant figures, the correct answer for the expression
\(\frac{0.02858 × 0.112}{ 0.5702}\)
will be

Compound ‘P’ on nitration with dil. HNO3 yields two isomers (A) and (B) show the intramolecular and intermolecular hydrogen bonding respectively. Compound (P) on reaction with conc. HNO3 yields a yellow compound ‘C’, a strong acid. The number of oxygen atoms is present in compound ‘C’ _____

A student needs to prepare a buffer solution of propanoic acid and its sodium salt with pH 4. The ratio of 
\(\frac{[CH_3CH_2COO^−]}{[CH_3CH_2COOH] }\)
required to make buffer is _____.
Given : Ka(CH3CH2COOH) = 1.3 × 10–5

For combustion of one mole of magnesium in an open container at 300K and 1bar pressure, ΔCHΘ=–601.70kJ mol–1, the magnitude of change in internal energy for the reaction is______ kJ. (Nearest integer) (Given : R = 8.3 J K–1 mol–1)
If the radius of the 3rd Bohr’s orbit of hydrogen atom is r3 and the radius of 4th Bohr’s orbit is r4. Then
The number of chiral alcohol(s) with molecular formula C4H10O is ____.
Fig. 













If the initial pressure of a gas 0.03 atm, the mass of the gas absorbed per gram of the adsorbent is ____× 10–2g

Which of the following will have maximum stabilization due to crystal field?
Which of the following structures are aromatic in nature?
Which of the following structures are aromatic in nature
L-isomer of a compound ‘A’ \((C_4H_8O_4)\) gives a positive test with \([Ag(NH_3)^2]^+\). Treatment of ‘A’ with acetic anhydride yields triacetate derivative. Compound ‘A’ produces an optically active compound (B) and an optically inactive compound (C) on treatment with bromine water and \(HNO_3\) respectively. Compound (A) is:
In isolation of which one of the following metals from their ores, the use of cyanide salt is not commonly involved?