List of top Questions asked in JEE Main

The rate constant for a first order reaction is given by the following equation :
$ln\ k=33.24−\frac {2.0×10^4\ K}{T}$
The activation energy for the reaction is given by ______ $kJ mol^{–1}$. (In nearest integer)
(Given : $R = 8.3 JK^{–1} mol^{–1}$)

It has been found that for a chemical reaction with rise in temperature by 9 K the rate constant gets doubled. Assuming a reaction to be occurring at 300 K, the value of activation energy is found to be _________kJ mol^–1. [nearest integer] (Given ln10 = 2.3, R = 8.3 J K^–1 mol^–1, log 2 = 0.30)

A radioactive element has a half life of 200 days. The percentage of original activity remaining after 83 days is ________. (Nearest integer) (Given : antilog 0.125 = 1.333, antilog 0.693 = 4.93)

[A] → [B]
Reactant Product
If formation of compound [B] follows the first order of kinetics and after 70 minutes the concentration of [A] was found to be half of its initial concentration. Then the rate constant of the reaction is x × 10^–6 s^–1. The value of x is _________. (Nearest Integer).

A compound’A’ on reaction with ‘X’ and ‘Y’ produces the same major product but differentby product’a’ and ‘b’. Oxidation of’a’ gives a substance produced by ants.

The cell potential for $\text{Zn}|\text{Zn}^{2+}\text{(aq)}||\text{Sn}^{x+}|\text{Sn}$ is 0.801 V at 298 K.The reaction quotient for the above reaction is 10^–2. The number of electrons involved in the given electrochemical cell reaction is _____. (Given: $Eº_Zn^{2+}$|Zn=-0.763V,Eºsn^x+|sn=+0.008V and 2.303RT/F=0.06V)

The solubility product of a sparingly soluble salt $A_2X_3$is $1.1 × 10^{–23}$. If the specific conductance of the solution is $3×10^{–5}$ S m^–1, the limiting molar conductivity of the solution is $x×10^{–3}$ S m² mol^–1. The value of x is _______.

The quantity of electricity of Faraday needed to reduce $1$ mol of $Cr_2O_7^{2-}$to $Cr^{3+}$ is

The amount of charge in F (Faraday) required to obtain one mole of iron from $Fe_3O_4$ is ______ . (Nearest integer)

The cell potential for the given cell at 298 K $\text{Pt} | \text{H}_2 \text{(g, 1 bar)} | \text{H}^+ \text{(aq)} || \text{Cu}^{2+} \text{(aq)} | \text{Cu(s)}$ is 0.31 V. The pH of the acidic solution is found to be 3, whereas the concentration of Cu²⁺ is 10^–x M. The value of x is _____.
(Given : $E^{Θ}_{Cu^{2+}/Cu}$ = 0.34 V and $\frac{2.303RT}{F}$ = 0.06 V)

The limiting molar conductivities of $NaI$, $NaNO_3$ and $AgNO_3$ are $12.7$, $12.0$ and $13.3$ mS m² mol^–1, respectively (all at 25°C). The limiting molar conductivity of $AgI$ at this temperature is ____ mS m² mol^–1.

For the reaction taking place in the cell:
Pt(s) | H₂(g) | H⁺ (q) || Ag⁺(aq) | Ag(s),
E^o_cell = + 0.5332 V.
The value of Δ_fG^o is _____kJ mol–1 [in nearest integer]

For the given reactions
Sn²⁺ + 2e^– → Sn
Sn⁴⁺ + 4e^– → Sn
the electrode potentials are;
$E^{∘}_{Sn^{2+}/Sn}=−0.140V $ and $E^{∘}_{Sn^{4+}Sn} =−0.010 V.$
The magnitude of standard electrode potential for $Sn^{4+}/Sn^{2+}$i.e.
$E^{∘}_{Sn^{4+}/Sn^{2+}}$
is _________ × 10^–2 V. (Nearest integer)