List of top Chemistry Questions asked in JEE Main

The electron in the hydrogen atom undergoes transition from higher orbitals to orbital of radius $211.6\, pm$. This transition is associated with

Given $E _{ Cl _{2} / Cl ^{-}}^{\circ}=1 . 36\, V,\, E _{ Cr ^{3+} / Cr }^{\circ}=-7 \cdot 74\, V$ $E _{ Cr _{2} O _{7}^{2-} / Cr ^{3+}}^{\circ}=1 .33\, V,\, E _{ MnO _{4}^{-} / Mn ^{2}+}^{\circ}=1. 51\, V$ Among the following, the strongest reducing agent is:

$\Delta U $ is equal to :

At $300\, K$, the density of a certain gaseous molecule at $2$ bar is double to that of dinitrogen $(N_2)$ at $4$ bar. The molar mass of gaseous molecule is :

Among the following, the incorrect statement is :

What is the standard reduction potential $(E^{\circ}) $ for ${Fe^{3+} \to Fe}$ ? Given that : ${Fe^{2+} + 2e^{-} -> Fe ; E^{\circ}_{Fe^{2+} / Fe} = - 0.47 V }$ ${Fe^{3+} + e^{-} -> Fe^{2+} ; E^{\circ}_{Fe^{3+} / Fe^{2+}} = + 0.77 V }$

$sp^3d^2$ hybridization is not displayed by :

Among the following, correct statement is :

Both lithium and magnesium display several similar properties due to the diagonal relationship; however, the one which is incorrect, is :

The electronic configuration with the highest ionization enthalpy is :

The group having triangular planar structures is :

A water sample has ppm level concentration of following anions $F^{-} = 10 ;\, SO^{2-}_4 = 100 ;\, NO^{-}_3 = 50$ The anion/anions that make/makes the water sample unsuitable for drinking is / are :

The radius of the second Bohr orbit for hydrogen atom is: (Planck's Const. $h =6 . 6262 \times 10^{-34}\, Js$; mass of electron $=9 . 1091 \times 10^{-31}\, Kg$ charge of electron $e =1 .60210 \times 10^{-19} C$; permittivity of vacuum $\left.\left(\epsilon_{0}\right)=8 \cdot 854185 \times 10^{-12}\, Kg ^{-1}\, m ^{-3} A ^{2}\right)$

Which of the following reactions is an example of a redox reaction?

On treatment of $100\, mL$ of $0.1\, M$ solution of $CoCl _{3} \cdot 6 H _{2} O$ with excess $AgNO _{3} ; 1.2 \times 10^{22}$ ions are precipitated. The complex is

A metal crystallises in a face centred cubic structure. If the edge length of its unit cell is $'a'$, the closest approach between two atoms in metallic crystal will be :

The rate of a reaction quadruples when the temperature changes from $300$ to $310\, K$. The activation energy of this reaction is : (Assume activation energy and pre-exponential factor are independent of temperature; $ln\, 2 = 0.693; R=8.314 \,J$ $mol^{-1} \, K^{-1}$)

The Tyndall effect is observed only when following conditions are satisfied (a) The diameter of the dispersed particles is much smaller than the wavelength of the light used. (b) The diameter of the dispersed particle is not much smaller than the wavelength of the light used (c) The refractive indices of the dispersed phase and dispersion medium are almost similar in magnitude (d) The refractive indices of the dispersed phase and dispersion medium differ greatly in magnitude

The number of $S=O$ and $S-OH$ bonds present in peroxodisulphuric acid and pyrosulphuric acid respectively are :

$XeF_6$ on partial hydrolysis with water produces a compound $'X'$. The same compound $'X'$ is formed when $XeF_6$ reacts with silica. The compound $'X'$ is :

An aqueous solution of a salt $MX_2$ at certain temperature has a van?t Hoff factor of 2. The degree of dissociation for this solution of the salt is :

Bromination of cyclohexene under conditions given below yields :

Which one of the following substances used in dry cleaning is a better strategy to control environmental pollution ?

Which one of the following statements about water is FALSE ?

A solid XY kept in an evacuated sealed container undergoes decomposition to form a mixture of gases X and Y at temperature T. The equilibrium pressure is 10 bar in this vessel. $K_p$ for this reaction is :