List of top Chemistry Questions asked in JEE Main

How many electrons are gained by MnO^Θ₄ in strongly alkaline medium?

Radius of the 2^nd orbit of He⁺ is r₀. Radius of the 4^th orbit of Be³⁺ is xr₀. Find x.

Some amount of urea is added to 1000 gm of H₂O due to which vapor pressure decreases by 25% of the original vapor pressure. Find out the mass of urea added (Round off to two decimal places)

Which of the following slows down the process of setting of the cement?

When 2 gm magnesium reasts with excess of HCl and H₂ gas is produced then the volume of H₂ gas produced is ____ × 10^–2liter at STP. (Nearest Integer)

IUPAC name of the compound C₇H₁₂O₂?

Match the terms in Column-I with their description in Column-II:

Column-I Column-II (P) N2O5 (i) N–N bond (Q) N2O (ii) N–O–N bond (R) N2O4 (iii) N=N / NN bond (S) NO2 (iv) N=O bond

Oxidation number of Mo in Ammonophosphomolybdate

Number of ambidentate ligands in given complex [M(en)(SCN)4] :

Which of the following slows down the process of setting of the cement ?

The value of log10K for a reaction A ⇋ B is (Given ΔHº298K = –54.67 kJmol–1 ΔSº298K = 10 kJmol–1 and R = 8.314 JK–1mol–1 2.303 × 8.314 × 298 = 5705)

If the radius of ground state hydrogen is 51 pm, find out the radius of 5th orbit of Li2+ ions. (closest integer)

In a container at a constant temperature , arrange the RMS velocity of the following: Ne, Cl₂ , UF₆

Match the Column:

	Column I		Column II
(A).	ClO₂^-	(1).	Linear
(B).	N₃^-	(2).	Tetrahedral
(C).	NH₄⁺	(3).	Bent
(D).	SF₄	(4).	See-Saw

Boiling point of a 2% aqueous solution of a non-volatile solute A is equal to the boiling point of 8% aqueous solution of a non-volatile solute B. The relation between molecular weights of A and B is

When a certain amount of solid A is dissolved in 100 g of water at 25°C to make a dilute solution, the vapour pressure of the solution is reduced to one-half of that of pure water. The vapour pressure of pure water is 23.76 mmHg. The number of moles of solute A added is _________. (Nearest Integer).

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.

Assertion A: A mixture contains benzoic acid and naphthalene. The pure benzoic acid can be separated out by the use of benzene.

Reason R: Benzoic acid is soluble in hot water.

In the light of the above statements, choose the most appropriate answer from the options given below.

In following pairs, the one in which both transition metal ions are colourless is :

A commercially sold conc. HCl is 35% HCl by mass. If the density of this commercial acid is 1.46 g/mL, the molarity of this solution is :
(Atomic mass : Cl = 35.5 amu, H = 1 amu)

When 800 mL of 0.5 M nitric acid is heated in a beaker, its volume is reduced to half and 11.5 g of nitric acid is evaporated. The molarity of the remaining nitric acid solution is $x × 10^{–2} M$. (Nearest integer)
(Molar mass of nitric acid is 63 g mol^–1)

The total number of $Mn=O$ bonds in $Mn_2O_7$ is ___.

1L aqueous solution of $H_2SO_4$ contains 0.02 m mol $H_2SO_4$. 50% of this solution is diluted with deionized water to give 1L solution (A). In solution (A), 0.01 m mol of $H_2SO_4$ are added. Total m mols of $H_2SO_4$ in the final solution is ______ $× 10^3$ m mols.

Given below are two statements. One is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: Energy of 2s orbital of hydrogen atom is greater than that of 2s orbital of lithium.
Reason R : Energies of the orbitals in the same subshell decrease with increase in the atomic number.
In the light of the above statements, choose the correct answer from the options given below.

The number of points, where the function $f: \mathbb{R} \to \mathbb{R}$, $$ f(x) = |x - 1|\cos|x - 2|\sin|x - 1| + (x - 3)|x^2 - 5x + 4|, $$ is NOT differentiable, is

The longest wavelength of light that can be used for the ionisation of lithium atom (Li) in its ground state is $x × 10^{–8}\ m$. The value of $x$ is ______. (Nearest Integer)
(Given : Energy of the electron in the first shell of the hydrogen atom is $2.2 \times 10^{–18} J$;
$h = 6.63 × 10^{–34}Js$ and $c = 3 × 10^8 ms^{–1}$)