List of top Chemistry Questions asked in JEE Main

Which one of the following ores is best concentrated by froth-flotation method?

Which of the following compounds is metallic and ferromagnetic ?

A particular adsorption process has the following characteristics : (i) It arises due to van der Waals forces and (ii) it is reversible. Identify the correct statement that describes the above adsorption process :

Consider the following sequence for aspartic acid : The pI (isoelectric point) of aspartic acid is :

The main oxides formed on combustion of $Li, Na$ and $K$ in excess of air are, respectively :

The volume of 0.1N dibasic acid sufficient to neutralize 1 g of a base that furnishes 0.04 mole of $OH^{-}$ in aqueous solution is :

Which of the following is an example of homoleptic complex?

The solubility of $N_2$ in water at 300 K and 500 torr partial pressure is 0.01 g $L^{-1}$. The solubility (in g $L^{-1}$) at 750 torr partial pressure is :

The concentration of fluoride, lead, nitrate and iron in a water sample from an underground lake was found to be $1000 \,ppb$, $40\, ppb$, $100\, ppm$ and $0.2\, ppm$, respectively. This water is unsuitable for drinking due to high concentration of :

Determination of the molar mass of acetic acid in benzene using freezing point depression is affected by :

Arrange the following amines in the order of increasing basicity.

The colour of $KMnO_4 $ is due to

Complete hydrolysis of starch gives :

Which of the vitamins given below is water soluble?

Which of the following pairs of compounds are positional isomers?

Gaseous $N_2O_4$ dissociates into gaseous $NO_2$ according to the reaction $N _{2} O _{4}( g ) \rightleftharpoons 2 NO _{2}( g )$ At $300\, K$ and $1\, atm$ pressure, the degree of dissociation of $N_2O_4$ is $0.2.$ If one mole of $N_2O_4$ gas is contained in a vessel, then the density of the equilibrium mixture is :

Choose the incorrect formula out of the four compounds for an element X below :

$3\,g$ of activated charcoal was added to $50\,mL$ of acetic acid solution ($0.06\,N$) in a flask. After an hour it was filtered and the strength of the filtrate was found to be $0.042\, N$. The amount of acetic acid adsorbed (per gram of charcoal) is

$A +2 B +3 C \rightleftharpoons AB _{2} C _{3}$ Reaction of $6.0\, g$ of $A , 6.0 \times 10^{23}$ atoms of $B$, and $0.036\, mol$ of $C$ yields $4.8\, g$ of compound $AB _{2} C _{3}$. If the atomic mass of $A$ and $C$ are 60 and 80 amu respectively, the atomic mass of $B$ is (Avogadro no. $=6 \times 10^{23}$ ):

A sample of a hydrate of barium chloride weighing $61\, g$ was heated until all the water of hydration is removed. The dried sample weighed $52\, g.$ The formula of the hydrated salt is : (atomic mass, $Ba = 137\, amu. Cl = 35.5\, amu$)

A solution at $20^{\circ}$C is composed of $1.5\, mol$ of benzene and $3.5\, mol$ of toluene. If the vapour pressure of pure benzene and pure toluene at this temperature are $74.7$ torr and $22.3$ torr, respectively, then the total vapour pressure of the solution and the benzene mole fraction in equilibrium with it will be, respectively :

At temperature T, the average kinetic energy of any particle is $\frac{3}{2}$ kT. The de Broglie wavelength follows the order :

Which of the following is the energy of a possible excited state of hydrogen?

At $298\, K$, the standard reduction potentials are $1.51\, V$ for $MnO _{4}^{-} \mid Mn ^{2+} 1.36\, V$ for $Cl _{2} \mid Cl ^{-} 1.07\, V$ for $Br _{2} \mid Br ^{-}$, and $0.54\, V$ for $\left. H _{2}\right|^{-}$. At $pH =3$, permanganate is expected to oxidize: $\left(\frac{R T}{F}=0.059\, V \right)$

The intermolecular interaction that is dependent on the inverse cube of distance between the molecules is