List of top Questions asked in JEE Main

Potassium chlorate is prepared by the electrolysis of KCl in basic solution

\(6\mathrm{OH^-} + \mathrm{Cl^-} \to \mathrm{ClO_3^-} + 3\mathrm{H_2O} + 6e^-\)

If only 60% of the current is utilized in the reaction, the time (rounded to the nearest hour) required to produce 10 g of \(\mathrm{KClO_3}\) using a current of 2 A is ______.

(Given : F = 96,500 C \(\mathrm{mol^{-1}}\); molar mass of \(\mathrm{KClO_3}\) = 122 g \(\mathrm{mol^{-1}}\))

A spherical balloon of radius 3 cm containing helium gas has a pressure of \(48 \times 10^{-3}\) bar. At the same temperature, the pressure, of a spherical balloon of radius 12 cm containing the same amount of gas will be ______ \(\times 10^{-6}\) bar.

Consider the Assertion and Reason given below.

Assertion (A) : Ethene polymerized in the presence of Ziegler Natta Catalyst at high temperature and pressure is used to make buckets and dustbins.

Reason (R) : High density polymers are closely packed and are chemically inert.

Choose the correct answer from the following:

The presence of soluble fluoride ion upto 1 ppm concentration in drinking water, is :

Among the sulphates of alkaline earth metals, the solubilities of BeSO₄ and MgSO₄ in water, respectively, are :

The number of Cl = O bonds in perchloric acid is, "________".

The incorrect statement is :

The increasing order of pK_b values of the following compounds is :

(I) 4-methoxy-N,N-dimethylaniline, (II) N,N-dimethylaniline, (III) N-methylaniline with CN at the meta position, (IV) N-methylaniline with OH at the meta position.

A solution of two components containing n₁ moles of the 1^st component and n₂ moles of the 2^nd component is prepared. M₁ and M₂ are the molecular weights of component 1 and 2 respectively. If d is the density of the solution in g mL^-1, C₂ is the molarity and x₂ is the mole fraction of the 2^nd component, then C₂ can be expressed as :

Which of the following compounds shows geometrical isomerism?

Arrange the following solutions in the decreasing order of pOH :

(A) 0.01 M HCl
(B) 0.01 M NaOH
(C) 0.01 M CH₃COONa
(D) 0.01 M NaCl

For the reaction

Fe₂N(s) + \(\frac{3}{2}\)H₂(g) \(\rightleftharpoons\) 2Fe(s) + NH₃(g)

The species that has a spin-only magnetic moment of 5.9 BM, is :
(T_d = tetrahedral)

The set that contains atomic numbers of only transition elements, is :

The variation of equilibrium constant with temperature is given below :

Temperature	Equilibrium Constant
T1 = 25\(^\circ\)C	K1 = 10
T2 = 100\(^\circ\)C	K2 = 100

The values of \(\Delta H^\circ\), \(\Delta G^\circ\) at T₁ and \(\Delta G^\circ\) at T₂ (in kJ mol^-1) respectively, are close to :
[Use R = 8.314 J K^-1 mol^-1]

Consider the following reactions

'A' is :

Consider the following reactions
A \(\rightarrow\) P₁ ; B \(\rightarrow\) P₂ ; C \(\rightarrow\) P₃ ; D \(\rightarrow\) P₄,
The order of the above reactions are a, b, c, and d, respectively. The following graph is obtained when log[rate] vs. log[conc.] are plotted

Among the following, the correct sequence for the order of the reactions is :

The lanthanoid that does NOT show +4 oxidation state is :

The major product obtained from the following reaction is :

The major products of the following reaction are :

The major product of the following reaction is :

Two bodies of the same mass are moving with the same speed, but in different directions in a plane. They have a completely inelastic collision and move together thereafter with a final speed which is half of their initial speed. The angle between the initial velocities of the two bodies (in degree) is ________.

Initially a gas of diatomic molecules is contained in a cylinder of volume V₁ at a pressure P₁ and temperature 250 K. Assuming that 25% of the molecules get dissociated causing a change in number of moles. The pressure of the resulting gas at temperature 2000 K, when contained in a volume 2V₁ is given by P₂ . The ratio \(\frac{P_2}{P_1}\) is ________.

The correct statement with respect to dinitrogen is :

An AC circuit has R= 100 \(\Omega\), C = 2 \(\mu\)F and L = 80 mH, connected in series. The quality factor of the circuit is :