List of top Chemistry Questions asked in JEE Main

The formulas of A and B for the following reaction sequence are

The correct sequential order of the reagents for the given reaction is

The products obtained from a reaction of hydrogen peroxide and acidified potassium permanganate are

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A : \(LiF\) is sparingly soluble in water.
Reason R : The ionic radius of \(Li^+\) ion is smallest among its group members, hence has least hydration enthalpy.
In the light of the above statements, choose the most appropriate answer from the options given below.

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R) :
Assertion (A) : Dissolved substances can be removed from a colloidal solution by diffusion through a parchment paper.
Reason (R) : Particles in a true solution cannot pass through parchment paper but the colloidal particles can pass through the parchment paper.
In the light of the above statements, choose the correct answer from the options given below

Outermost electronic configurations of four elements A,B,C,D are given below:
(A) 3s² (B) s²3p¹ (C) 3s²3p³ (D) 3s²3p⁴
The correct order of fist ionization enthalpy for them is:

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: Boric acid is a weak acid
Reason R: Boric acid is not able to release \(H^+\) ion on its own. It receives \(OH^–\) ion from water and releases \(H^+\) ion.
In the light of the above statements, choose the most appropriate answer from the options given below.

The metal complex that is diamagnetic is (Atomic number : \(Fe, 26; Cu, 29\))

Match List I with List II.

List I Pollutant	List II Source
A. Microorganisms	I. Strip mining
B. Plant nutrients	II. Domestic sewage
C. Toxic heavy metals	III. Chemical fertilizer
D. Sediment	IV. Chemical factory

Choose the correct answer from the options given below:

The correct decreasing order of priority of functional groups in naming an organic compound as per IUPAC system of nomenclature is

An element A of group1 shows similarity to an element B belonging to group 2. If A has maximum hydration enthalpy in group 1 then B is:

Which of the following is not an example of benzenoid compound?

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R)
Assertion (A) : Boron is unable to form BF₆^3-Reason (R) : Size of B is very small
In the light of the above statements, choose the correct answer from the options given below:

Hydrolysis of which compound will give carbolic acid?

In neutral or alkaline solution, MnO₄^– oxidises thiosulphateto :

Low oxidation state of metals in their complexes are common when ligands :

Given below are two statements:
Statement I : The non bio-degradable fly ash and slag from steel industry used by cement industry.
Statement II : The fuel obtained from plastic waste is lead free.
In the light of the above statements, choose the most appropriate answer from the options given below:

Ka₁, Ka₂ and Ka₃ are the respective ionization constants for the following reactions (a),(b), and (c).
(a) H₂C₂O₄⇌H⁺+HC₂O₄⁻
(b) HC₂O₄⁻⇌H⁺+HC₂O₄²⁻
(c) H₂C₂O₄⇌2H⁺+_C2O₄²⁻
The relationship between Ka₁,Ka₂ and Ka₃ is given as

Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: Phenolphthalein is a pH dependent indicator, remains colourless in acidic solution and gives pink colour in basic medium.
Reason R: Phenolphthalein is a weak acid. It doesn’t dissociate in basic medium.
In the light of the above statements, choose the most appropriate answer from the options given below.

Which of the following enhances the lathering property of soap?

The normality of H₂SO₄ in the solution obtained on mixing 100 mL of 0.1 M H₂SO₄ with 50 mL of 0.1 M NaOH is ________ × 10^–1 N. (Nearest Integer)

For a real gas at 25°C temperature and high pressure (99 bar) the value of the compressibility factor is 2, so the value of van der Waal’s constant ‘b’ should be ______ × 10^–2 L mol^–1 (Nearest integer).
(Given R=0.083 L bar K-1 mol-1)

A gas (Molar mass = 280 g mol^–1) was burnt in excess O₂ in a constant volume calorimeter and during combustion the temperature of calorimeter increased from 298.0 K to 298.45 K. If the heat capacity of calorimeter is 2.5 kJ K^–1 and enthalpy of combustion of gas is 9 kJ mol^–1 then amount of gas burnt is __________g. (Nearest Integer).

[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).

Among the following ores Bauxite, Siderite, Cuprite, Calamine, Haematite, Kaolinite, Malachite, Magnetite, Sphalerite, Limonite, Cryolite, the number of principal ores of iron is____.