List of top Questions asked in JEE Main- 2026

\(t_{100\%}\) is the time required for 100% completion of a reaction, while \(t_{1/2}\) is the time required for 50% completion of the reaction. Which of the following correctly represents the relation between \(t_{100\%}\) and \(t_{1/2}\) for zero order and first order reactions respectively

One mole of an alkane (\(x\)) requires 8 mole oxygen for complete combustion. Sum of number of carbon and hydrogen atoms in the alkane (\(x\)) is ______.

For reaction \(A \rightarrow P\), rate constant \(k = 1.5 \times 10^3\ s^{-1}\) at \(27^\circ C\). If activation energy for the above reaction is \(60\ kJ\ mol^{-1}\), then the temperature (in \(^{\circ}C\)) at which rate constant \(k = 4.5 \times 10^3\ s^{-1}\) is ______. (Nearest integer) \[ \text{Given: } \log 2 = 0.30,\ \log 3 = 0.48,\ R = 8.3\ J\ K^{-1}\ mol^{-1},\ \ln 10 = 2.3 \]

At the transition temperature \(T\), \(A \rightleftharpoons B\) and \(\Delta G^\circ = 105 - 35\log T\), where \(A\) and \(B\) are two states of substance \(X\). The transition temperature in \(^{\circ}C\) when pressure is 1 atm is ______.

If for \( 3 \leq r \leq 30 \), \[ \binom{30}{30-r} + 3\binom{30}{31-r} + 3\binom{30}{32-r} + \binom{30}{33-r} = \binom{m}{r}, \] then \( m \) equals: ________ 

The number of points in the interval \( [2, 4] \), at which the function \( f(x) = \left\lfloor x^2 - x - \frac{1}{2} \right\rfloor \), where \( \left\lfloor \cdot \right\rfloor \) denotes the greatest integer function, is discontinuous, is _______.
If X and Y are the inputs, the given circuit works as _______.

If a body of mass 1 kg falls on the earth from infinity, it attains velocity \( v \) and kinetic energy \( k \) on reaching the surface of the earth. The values of \( v \) and \( k \) respectively are _______.

The equation of motion of a particle is given by \( x = a \sin \left( 50t + \frac{\pi}{3} \right) \, \text{cm}. \) The particle will come to rest at time \( t_1 \) and it will have zero acceleration at time \( t_2 \). The \( t_1 \) and \( t_2 \) respectively are _______.

The binding energy per nucleon of \(^{209} \text{Bi}\)  is _______ MeV. \[ \text{Take } m(^{209} \text{Bi}) = 208.98038 \, \text{u}, \, m_p = 1.007825 \, \text{u}, \, m_n = 1.008665 \, \text{u}, \, 1 \, \text{u} = 931 \, \text{MeV}/c^2. \]

Identify compounds A and E in the following reaction sequence.

Let \[ \alpha = \frac{1}{4} + \frac{1}{8} + \frac{1}{16} + \dots \infty \] and \[ \beta = \frac{1}{3} + \frac{1}{9} + \frac{1}{27} + \dots \infty. \] 
Then the value of \[ (0.2)^{\log_{\sqrt{5}}(\alpha)} + (0.04)^{\log_{5}(\beta)} \] is equal to: ________

Let \( y = y(x) \) be the solution of the differential equation: 
\[ \frac{dy}{dx} + \left( \frac{6x^2 + (3x^2 + 2x^3 + 4)e^{-2x}}{(x^3 + 2)(2 + e^{-2x})} \right)y = 2 + e^{-2x}, \quad x \in (-1, 2) \] 
satisfying \( y(0) = \frac{3}{2} \). 
If \( y(1) = \alpha \left(2 + e^{-2}\right) \), then the value of \( \alpha \) is ________.

In sulphur estimation, \(2.0 \times 10^{-3}\) mol of an organic compound (X) (molar mass 76 \(g \cdot mol^{-1}\)) gave 0.4813 g of barium sulphate (molar mass 233 \(g \cdot mol^{-1}\)). The percentage of sulphur in the compound (X) is _______ \(\times 10^{-1}\) % (Nearest integer)
For the following reaction at 50 \(^\circ\)C and at 2 atm pressure,
\(2N_2O_5(g) \rightleftharpoons 2N_2O_4(g) + O_2(g)\)
\(N_2O_5\) is 50% dissociated. The magnitude of standard free energy change at this temperature is x.
x = _______ J \(\cdot mol^{-1}\) [Nearest integer].
Given : R = 8.314 J \(mol^{-1} K^{-1}\), \(\log 2 = 0.30, \log 3 = 0.48, \ln 10 = 2.303, ^\circ C + 273 = K\)
For a first order reaction \(A \to B\),
x = _______ min. (Nearest integer)
If 3.365 g of ethanol (l) is burnt completely in a bomb calorimeter at 298.15 K, the heat produced is 99.472 kJ. The \(|\Delta H_f^\circ|\) of ethanol at 298.15 K is _______ \(\times 10^2\) kJ \(\cdot mol^{-1}\). (Nearest integer)
Given: Standard enthalpy for combustion of graphite = \(-393.5\) kJ \(\cdot mol^{-1}\)
Standard enthalpy of formation of water (l) = \(-285.8\) kJ \(\cdot mol^{-1}\)
Molar mass in \(g \cdot mol^{-1}\) of C, H, O are 12, 1 and 16 respectively
An electrochemical cell, consist of the following two redox couples, \(M^{x+}(aq)/M(s) [E_{red}^\circ = +0.15 V]\) and \(Fe^{3+}(aq)/Fe(s) [E_{red}^\circ = -0.036 V]\). The cell EMF (\(E_{cell}\)) is recorded to be 0.2057 V. If the reaction quotient of the electrochemical cell is found to be \(10^{-z}\), then the value of x is _________. (Nearest integer)
[Given : M is a p-block metal and \(\frac{2.303 RT}{F} = 0.059 V\)]
Match the LIST-I with LIST-II:
Among \(Fe^{3+}, Pb^{2+}, Cu^{2+}\) and \(Mn^{2+}\), identify the one that gets precipitated out while passing \(H_2S\) in presence of \(NH_4OH\) as group reagent. The highest possible oxidation state of the corresponding metal is:
Compound (X) [Phenylacetylene] is subjected to the sequence of reactions:
Molar mass of the major product (Y) formed is _______ \(g \cdot mol^{-1}\). (Given molar mass in \(g \cdot mol^{-1}\) C:12, H: 1, O: 16)
The strongest conjugate acid will result from:
The descending order of acidity among the following compounds is :
Three different reactions were started with identical initial concentration of reactants. Which of the following statement is correct regarding the given graph showing variation of reactant concentration with time?
The following structures are: