List of top Chemistry Questions asked in JEE Main

The heat of formation of \( \text{SO}_2(g) \) is given by: \[ S(g) + \frac{3}{2} O_2(g) \rightarrow SO_3(g) + 2x \, \text{kcal} \] \[ SO_2(g) + \frac{1}{2} O_2(g) \rightarrow SO_3(g) + y \, \text{kcal} \]
Which of the following arrangements with respect to their reactivity in nucleophilic addition reaction is correct?

The steam volatile compounds among the following are:

Choose the correct answer from the options given below:
 

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

The product (A) formed in the following reaction sequence is:


 

Which of the following oxidation reactions are carried out by both \( K_2Cr_2O_7 \) and \( KMnO_4 \) in acidic medium? A. \( I^- \rightarrow I_2 \) B. \( S^{2-} \rightarrow S \) C. \( Fe^{2+} \rightarrow Fe^{3+} \) D. \( I^- \rightarrow IO_3^- \) E. \( S_2O_3^{2-} \rightarrow SO_4^{2-} \) Choose the correct answer from the options given below:

Given below are two statements: 
Statement (I): The first ionization energy of Pb is greater than that of Sn. 
Statement (II): The first ionization energy of Ge is greater than that of Si. 

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

Match the LIST-I with LIST-II (Redox Reactions).
Redox Reaction;type of Redox Reaction
Choose the correct answer from the options given below:

$\mathrm{KMnO}_{4}$ acts as an oxidising agent in acidic medium. ' X ' is the difference between the oxidation states of Mn in reactant and product. ' Y ' is the number of ' d ' electrons present in the brown red precipitate formed at the end of the acetate ion test with neutral ferric chloride. The value of $\mathrm{X}+\mathrm{Y}$ is _______ .

Given below are two statements:

Statement (I): The first ionization energy of Pb is greater than that of Sn.
Statement (II): The first ionization energy of Ge is greater than that of Si.

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

Which of the following oxidation reactions are carried out by both \( K_2Cr_2O_7 \) and \( KMnO_4 \) in acidic medium?
A. \( I^- \rightarrow I_2 \)
B. \( S^{2-} \rightarrow S \)
C. \( Fe^{2+} \rightarrow Fe^{3+} \)
D. \( I^- \rightarrow IO_3^- \)
E. \( S_2O_3^{2-} \rightarrow SO_4^{2-} \)
Choose the correct answer from the options given below:
The standard reduction potential values of some of the p-block ions are given below. Predict the one with the strongest oxidizing capacity.
The species which does not undergo disproportionation reaction is:

In Carius method for estimation of halogens, 180 mg of an organic compound produced 143.5 mg of AgCl. The percentage composition of chlorine in the compound is ___________%. [Given: Molar mass in g mol\(^{-1}\) of Ag = 108, Cl = 35.5]

Given below are two statements: Statement (I): The boiling points of alcohols and phenols increase with increase in the number of C-atoms.
Statement (II): The boiling points of alcohols and phenols are higher in comparison to other classes of compounds such as ethers and haloalkanes. In the light of the above statements, choose the correct answer from the options given below:
Consider an elementary reaction: \[ A(g) + B(g) \rightarrow C(g) + D(g) \] If the volume of the reaction mixture is suddenly reduced to \( \frac{1}{3} \) of its initial volume, the reaction rate will become \( x \) times of the original reaction rate. The value of \( x \) is:
The purification method based on the following physical transformation is: \[ {Solid} \xrightarrow{{Heat}} {Vapour} \xrightarrow{{Cool}} {Solid} \]

The major product of the following reaction is: 


 

Identify correct statements: (A) Primary amines do not give diazonium salts when treated with \({NaNO}_2\) in acidic condition.
(B) Aliphatic and aromatic primary amines on heating with \({CHCl}_3\) and ethanolic \({KOH}\) form carbylamines.
(C) Secondary and tertiary amines also give carbylamine test.
(D) Benzenesulfonyl chloride is known as Hinsberg’s reagent.
(E) Tertiary amines react with benzenesulfonyl chloride very easily.
Choose the correct answer from the options given below:

The descending order of basicity of following amines is :

Choose the correct answer from the options given below :

The correct order of basic strength of the following molecules is:
(A) \(\text{C}_6\text{H}_4\text{NH}_2\text{O}\)
(B) \(\text{C}_6\text{H}_4\text{NH}_2\text{MeO}\)
(C) \(\text{C}_6\text{H}_4\text{NH}_2\text{NO}_2\)
(D) \(\text{C}_6\text{H}_4\text{NH}_2\text{CH}_3\)
In the reaction \( 2A + B \rightarrow C \), if the rate law is \( \text{Rate} = k[A]^2[B] \), what is the overall order of the reaction?
Consider an elementary reaction: \[ A(g) + B(g) \rightarrow C(g) + D(g) \] If the volume of the reaction mixture is suddenly reduced to \( \frac{1}{3} \) of its initial volume, the reaction rate will become \( x \) times of the original reaction rate. The value of \( x \) is:
The molecule A changes into its isomeric form B by following a first order kinetics at a temperature of 1000 K. If the energy barrier with respect to reactant energy for such isomeric transformation is 191.48 kJ mol\(^{-1}\) and the frequency factor is \(10^{20}\), the time required for 50% molecules of A to become B is ________________________ picoseconds (nearest integer). [R = 8.314 J K\(^{-1}\) mol\(^{-1}\)]
In a first order decomposition reaction, the time taken for the decomposition of reactant to one fourth and one eighth of its initial concentration are $ t_1 $ and $ t_2 $ (s), respectively. The ratio $ t_1 / t_2 $ will be: