List of top Chemistry Questions asked in JEE Main

A $p$-block element $E$ and hydrogen form a binary cation $ (EH_x)^+ $, while $EH_3$ on treatment with $K_2HgI_4$ in alkaline medium gives a precipitate of basic mercury(II) amido-iodide. Given below are first ionisation enthalpy values (kJ mol$^{-1}$) for the first elements each from groups 13, 14, 15 and 16. Identify the correct first ionisation enthalpy value for element $E$.

$A \rightarrow \text{Product}$ (First order reaction). Three sets of experiments were performed for a reaction under similar experimental conditions: \[ \text{Run 1} \Rightarrow 100\ \text{mL of } 10\ \text{M solution of reactant } A \] \[ \text{Run 2} \Rightarrow 200\ \text{mL of } 10\ \text{M solution of reactant } A \] \[ \text{Run 3} \Rightarrow 100\ \text{mL of } 10\ \text{M solution of reactant } A + 100\ \text{mL of } H_2O \] The correct variation of rate of reaction is

In the reaction, \[ 2\text{Al}(s) + 6\text{HCl}(aq) \rightarrow 2\text{Al}^{3+}(aq) + 6\text{Cl}^-(aq) + 3\text{H}_2(g) \]

The temperature at which the rate constants of the given below two gaseous reactions become equal is ____________ K (Nearest integer).
\[ X \longrightarrow Y, \qquad k_1 = 10^{6} e^{-\frac{30000}{T}} \] \[ P \longrightarrow Q, \qquad k_2 = 10^{4} e^{-\frac{24000}{T}} \] Given: $ \ln 10 = 2.303 $

The correct order of the rate of reaction of the following reactants with nucleophile by $ \mathrm{S_N1} $ mechanism is:
(Given: Structures I and II are rigid)

Given below are two statements:
Statement I: The Henry’s law constant $ K_H $ is constant with respect to variations in solution concentration over the range for which the solution is ideally dilute.
Statement II: $ K_H $ does not differ for the same solute in different solvents.
In the light of the above statements, choose the correct answer from the options given below.

Given below are two statements:
Statement I: Phenol on treatment with $ \mathrm{CHCl_3/aq.\ KOH} $ under refluxing condition, followed by acidification produces p-hydroxy benzaldehyde as the major product and o-hydroxy benzaldehyde as the minor product.
Statement II: The mixture of p-hydroxybenzaldehyde and o-hydroxybenzaldehyde can be easily separated through steam distillation.
In the light of the above statements, choose the correct answer from the options given below

Match the LIST-I with LIST-II.

Choose the correct answer from the options given below:

The cycloalkene (X) on bromination consumes one mole of bromine per mole of (X) and gives the product (Y) in which C : Br ratio is $3:1$. The percentage of bromine in the product (Y) is _________ % (Nearest integer).
Given:
\[ \text{H} = 1,\quad \text{C} = 12,\quad \text{O} = 16,\quad \text{Br} = 80 \]

Consider the following data :
$ \Delta_f H^\ominus (\text{methane, g}) = -X \text{ kJ} mol^{-1} $
Enthalpy of sublimation of graphite $ = Y \text{ kJ mol}^{-1} $
Dissociation enthalpy of $ H_2 = Z \text{ kJ mol}^{-1} $
The bond enthalpy of C-H bond is given by :}

Decomposition of A is a first order reaction at T(K) and is given by $ A(g) \rightarrow B(g) + C(g) $.
In a closed 1 L vessel, 1 bar A(g) is allowed to decompose at T(K). After 100 minutes, the total pressure was 1.5 bar. What is the rate constant (in $ min^{-1} $) of the reaction ? ($ \log 2 = 0.3 $)

The osmotic pressure of a living cell is 12 atm at 300 K. The strength of sodium chloride solution that is isotonic with the living cell at this temperature is ____________ g L$^{-1}$. (Nearest integer)
Given: R = 0.08 L atm K$^{-1}$ mol$^{-1}$
Assume complete dissociation of NaCl
(Given : Molar mass of Na and Cl are 23 and 35.5 g mol$^{-1}$ respectively.)

The correct increasing order of C-H(A), C-O(B), C=O(C) and C$\equiv$N(D) bonds in terms of covalent bond length is :

Consider the following spectral lines for atomic hydrogen :
A. First line of Paschen series
B. Second line of Balmer series
C. Third line of Paschen series
D. Fourth line of Bracket series
The correct arrangement of the above lines in ascending order of energy is :

The correct statements are :
A. Activation energy for enzyme catalysed hydrolysis of sucrose is lower than that of acid catalysed hydrolysis.
B. During denaturation, secondary and tertiary structures of a protein are destroyed but primary structure remains intact.
C. Nucleotides are joined together by glycosidic linkage between $ C_1 $ and $ C_4 $ carbons of the pentose sugar.
D. Quaternary structure of proteins represents overall folding of the polypeptide chain.
Choose the correct answer from the options given below :

Match List - I with List - II.

Choose the correct answer from the options given below :

Consider the following sequence of reactions. The number of bromine atom(s) in the final product (P) will be :

The correct order of reactivity of the following benzyl halides towards reaction with KCN is :

MX is a sparingly soluble salt that follows the given solubility equilibrium at 298 K.
MX(s) $\rightleftharpoons M^{+(aq) }+ X^{-}(aq)$; $K_{sp} = 10^{-10}$
If the standard reduction potential for $M^{+}(aq) + e^{-} \rightarrow M(s)$ is $(E^{\circ}_{M^{+}/M}) = 0.79$ V, then the value of the standard reduction potential for the metal/metal insoluble salt electrode $E^{\circ}_{X^{-}/MX(s)/M}$ is ____________ mV. (nearest integer)
[Given : $\frac{2.303 RT}{F} = 0.059$ V]