List of top Chemistry Questions asked in JEE Main

If $ {A}_2{B} $ is 30% ionised in an aqueous solution, then the value of van't Hoff factor $ i $ is:

Given below are some nitrogen containing compounds:

Each of them is treated with HCl separately. 1.0 g of the most basic compound will consume ....... mg of HCl.
(Given Molar mass in g mol$^{-1}$: C: 12, H: 1, O: 16, Cl: 35.5.)

An element 'E' has the ionisation enthalpy value of 374 kJ mol$^{-1}$. 'E' reacts with elements A, B, C, and D with electron gain enthalpy values of $ -328 $, $ -349 $, $ -325 $, and $ -295 $ kJ mol$^{-1}$, respectively. The correct order of the products EA, EB, EC, and ED in terms of ionic character is:

For a $ {Mg} | {Mg}^{2+}(aq) || {Ag}^{+}(aq) | {Ag} $, the correct Nernst Equation is:

The steam volatile compounds among the following are:

Choose the correct answer from the options given below:

At temperature T, compound $ {AB}_2 $ dissociates as $ {AB}_2 \rightleftharpoons {A} + \frac{1}{2} {B}_2 $, having degree of dissociation $ x $ (small compared to unity). The correct expression for $ x $ in terms of $ K_p $ and $ p $ is:

Match List - I with List - II: List - I: (A) $ {[MnBr}_4]^{2-} $
(B) $ {[FeF}_6]^{3-} $
(C) $ {[Co(C}_2{O}_4)_3]^{3-} $
(D) $ [Ni(CO)_4] $
List - II: (I) $ d^2sp^3 $ & diamagnetic
(II) $ sp^2d^2 $ & paramagnetic
(III) $ sp^3 $ & diamagnetic
(IV) $ sp^3 $ & paramagnetic
Choose the correct answer from the options given below:

The product (P) formed in the following reaction is:

Given below are two statements: Statement (I): The radius of isoelectronic species increases in the order. \[ {Mg}^{2+}<{Na}^+<{F}^-<{O}^{2-} \] Statement (II): The magnitude of electron gain enthalpy of halogens decreases in the order. \[ {Cl}>{F}>{Br}>{I} \] In light of the above statements, choose the most appropriate answer from the options given below:

In the following substitution reaction:

The correct increasing order of stability of the complexes based on $ \Delta $ value is:

Match List - I with List - II.

For the reaction:

The correct order of set of reagents for the above conversion is :

In Carius method of estimation of halogen, 0.25 g of an organic compound gave 0.15 g of silver bromide (AgBr). The percentage of Bromine in the organic compound is $\_\_\_\_$times 10^{-1}% (Nearest integer). (Given: Molar mass of Ag is 108 and Br is 80 g mol^{-1}

The observed and normal molar masses of compound MX$_2$ are 65.6 and 164 respectively. The percent degree of ionisation of MX$_2$ is $\_\_\_\_$% (Nearest integer).

The possible number of stereoisomers for 5-phenylpent-4-en-2-ol is:

The hydrocarbon (X) with molar mass 80 g mol$^{-1}$ and 90% carbon has $\_\_\_\_$ degree of unsaturation.

Consider a complex reaction taking place in three steps with rate constants $k_1$, $k_2$, and $k_3$ respectively. The overall rate constant $k$ is given by the expression $ k = \sqrt{\frac{k_1 k_3}{k_2}} $. If the activation energies of the three steps are 60, 30, and 10 kJ mol$^{-1}$ respectively, then the overall energy of activation in kJ mol$^{-1}$ is $\_\_\_\_$(Nearest integer).

The sum of sigma ($ \sigma $) and pi ($ \pi $) bonds in Hex-1,3-dien-5-yne is:

The standard reduction potential values of some of the p-block ions are given below. Predict the one with the strongest oxidising capacity.

The molar conductivity of a weak electrolyte when plotted against the square root of its concentration, which of the following is expected to be observed?

The products A and B in the following reactions, respectively, are:

The correct order of stability of following carbocations is:

Given below are two statements:
Statement I: In the oxalic acid vs KMnO$_4$ (in the presence of dil H$_2$SO$_4$) titration the solution needs to be heated initially to 60°C, but no heating is required in Ferrous ammonium sulphate (FAS) vs KMnO$_4$ titration (in the presence of dil H$_2$SO$_4$).

Statement II: In oxalic acid vs KMnO$_4$ titration, the initial formation of MnSO$_4$ takes place at high temperature, which then acts as catalyst for further reaction. In the case of FAS vs KMnO$_4$, heating oxidizes Fe$^{2+}$ into Fe$^{3+}$ by oxygen of air and error may be introduced in the experiment.

In the light of the above statements, choose the correct answer from the options given below:

A molecule (P) on treatment with acid undergoes rearrangement and gives (Q). (Q) on ozonolysis followed by reflux under alkaline condition gives (R). The structure of (R) is given below. The structure of (P) is: