List of top Chemistry Questions asked in JEE Main

\[ 2 \text{MnO}_4^{-} + b \text{I}^{-} + c \text{H}_2\text{O} \rightarrow x \text{I}_2 + y \text{MnO}_2 + z \text{OH}^{-} \]
If the above equation is balanced with integer coefficients, the value of \( z \) is \( \_\_\_\_\_\_ \).

Given below are two statement one is labeled as Assertion (A) and the other is labeled as Reason (R).
Assertion (A): CH₂ = CH – CH₂ – Cl is an example of allyl halide
Reason (R): Allyl halides are the compounds in which the halogen atom is attached to sp² hybridised carbon atom.
In the light of the two above statements, choose the most appropriate answer from the options given below

In the given reactions identify the reagent A and reagent B

The order of relative stability of the contributing structure is:

Choose the correct answer from the options given below:

How many of the following vitamins are stored in Human Body?
A, B, C, D, E, K?

Which of the following statements is not correct about rusting of iron?

The final product A, formed in the following reaction sequence is:

The technique used for purification of steam volatile water immiscible substance is:

The pH at which Mg(OH)\(_2\) \([K_{sp} = 1 \times 10^{-11}]\) begins to precipitate from a solution containing 0.10 M Mg\(^{2+}\) ions is \( \_\_\_\_ \).

If IUPAC name of an element is “Unununnium” then the element belongs to nth group of periodic table. The value of n is______

Following is a confirmatory test for aromatic primary amines. Identify reagent (A) and (B)

On a thin layer chromatographic plate, an organic compound moved by 3.5 cm, while the solvent moved by 5 cm. The retardation factor of the organic compound is \( \_\_\_\_ \times 10^{-1} \).

The Lassaigne’s extract is boiled with dil HNO\(_3\) before testing for halogens because

Choose the correct option having all the elements with \( d^{10} \) electronic configuration from the following:

Structure of 4-Methylpent-2-enal is

Given below are the two statements: one is labelled as Assertion (A) and the other is labeled as Reason (R).
Assertion (A): There is a considerable increase in covalent radius from N to P. However from As to Bi only a small increase in covalent radius is observed.
Reason (R): covalent and ionic radii in a particular oxidation state increases down the group.
In the light of the above statement, choose the most appropriate answer from the options given below:

The compound formed by the reaction of ethanal with semicarbazide contains _____number of nitrogen atoms.

Choose the correct statements from the following:
A Ethane-1,2-diamine is a chelating ligand.
B Metallic aluminium is produced by electrolysis of aluminium oxide in presence of cryolite.
C Cyanide ion is used as a ligand for leaching of silver.
D Phosphine acts as a ligand in Wilkinson catalyst.
E The stability constants of \( \text{Ca}^{2+} \) and \( \text{Mg}^{2+} \) are similar to EDTA complexes.

What happens to freezing point of benzene when small quantity of napthalene is added to benzene?

Example of vinylic halide is

Match List-I with List-II
\[ \begin{array}{|c|c|} \hline \text{List-I (Species)} & \text{List-II (Electronic distribution)} \\ \hline \text{(A) Cr}^{+2} & \text{(I) } 3d^8 \\ \text{(B) Mn}^{+} & \text{(II) } 3d^3 4s^1 \\ \text{(C) Ni}^{+2} & \text{(III) } 3d^4 \\ \text{(D) V}^{+} & \text{(IV) } 3d^5 4s^1 \\ \hline \end{array} \]

Calculate the Molarity of a Solution having density = \(1.5\) \(g/ml\). \(\%(w/w)\) of Solute is \(36\%\) and Molecular weight of Solute is \(36\) \(g/mol\)

The number of correct reaction(s) among the following is ________.

Match List -I with List II:

Choose the correct answer from the options given below :

The correct sequence of ligands in the order of decreasing field strength is :