List of top Chemistry Questions asked in JEE Main

Density of 3 M NaCl solution is 1.25 g/mL. The molality of the solution is:

20 mL of 2 M NaOH solution is added to 400 mL of 0.5 M NaOH solution. The final concentration of the solution is $\_\_\_\_\_$ x $10^{-2}$M. (Nearest integer)

The purification method based on the following physical transformation is: \[ {Solid} \xrightarrow{{Heat}} {Vapour} \xrightarrow{{Cool}} {Solid} \]

Arrange the following in increasing order of solubility product: \[ {Ca(OH)}_2, {AgBr}, {PbS}, {HgS} \]

Concentrated nitric acid is labelled as 75%by mass. The volume in mL of the solution which contains 30 g of nitric acid is: Given: Density of nitric acid solution is 1.25 g/mL.

0.1 M solution of KI reacts with excess of $ \text{H}_2\text{SO}_4 $ and KIO$_3$, according to the equation: \[ 5I^- + 6H^+ \rightarrow 3I_2 + 3H_2O \]

Identify the correct statements:

(A) 200 mL KI solution reacts with 0.004 mol of KIO₃
(B) 200 mL KI solution reacts with 0.006 mol of H₂SO₄
(3) 0.5 L KI solution produced 0.005 mol of I₂
(4) Equivalent weight of KIO₃ is equal to Molecular weight / 5

An aqueous solution of 0.1 M HA shows depression in freezing point of 0.2°C. If $ K_f $ (H$_2$O) = 1.86 K kg mol$^{-1}$ and assuming molarity = molality, find the dissociation constant of HA.

Which of the following solutions can form a minimum boiling azeotrope?

Which of the following binary mixture does not show the behavior of minimum boiling azeotropes?

Sea water, which can be considered as a 6 molar (6 M) solution of NaCl, has a density of 2 g mL$^{-1}$. The concentration of dissolved oxygen (O$_2$) in sea water is 5.8 ppm. Then the concentration of dissolved oxygen (O$_2$) in sea water, in x $\times$ 10$^{-4}$ m. x = _______. (Nearest integer)
Given: Molar mass of NaCl is 58.5 g mol$^{-1}$Molar mass of O$_2$ is 32 g mol$^{-1}$.

An aqueous solution of HCl with pH 1.0 is diluted by adding equal volume of water (ignoring dissociation of water). The pH of HCl solution would be: $ \text{(Given log 2 = 0.30)} $

10 mL of 2 M NaOH solution is added to 20 mL of 1 M HCl solution kept in a beaker. Now, 10 mL of this mixture is poured into a volumetric flask of 100 mL containing 2 moles of HCl and made the volume upto the mark with distilled water. The solution in this flask is :

Liquid A and B form an ideal solution. The vapour pressure of pure liquids A and B are 350 and 750 mm Hg respectively at the same temperature. If $ x_A $ and $ x_B $ are the mole fraction of A and B in solution while $ y_A $ and $ y_B $ are the mole fraction of A and B in vapour phase then :

Match List-I with List-II

Choose the correct answer from the options given below :

If equal volumes of AB and XY (both are salts) aqueous solutions are mixed, which of the following combination will give precipitate of AY, at 300 K?

The structure of the major product formed in the following reaction is:

The steam volatile compounds among the following are:

An octahedral complex having molecular composition Co.5NH$_3$.Cl.SO$_4$ has two isomers A and B. The solution of A gives a white precipitate with AgNO$_3$ solution and the solution of B gives a white precipitate with BaCl$_2$ solution. The type of isomerism exhibited by the complex is,

The number of paramagnetic complexes among $[FeF_6]^{3-}, [Fe(CN)_6]^{3-}, [Mn(CN)_6]^{3-}, [Co(C_2O_4)_3]^{3-}, [MnCl_6]^{3-}$ and $[CoF_6]^{3-}$, which involved $d^2sp^3$ hybridization is ...............

For the thermal decomposition of $ N_2O_5(g) $ at constant volume, the following table can be formed, for the reaction mentioned below: \[ 2 N_2O_5(g) \rightarrow 2 N_2O_4(g) + O_2(g) \] Given: Rate constant for the reaction is $ 4.606 \times 10^{-2} \text{ s}^{-1} $.

The Maximum number of RBr producing 2-methylbutane by above sequence of reaction

Consider the given figure and choose the correct option:

When sec-butylcyclohexane reacts with bromine in the presence of sunlight, the major product is:

Consider the following reactions: \[ K_2Cr_2O_7 + 2 KOH \xrightarrow{ \text{heat} } [A] \] \[ [A] + H_2SO_4 \xrightarrow{} [B] + K_2SO_4 \] The products [A] and [B], respectively are:

In the Claisen-Schmidt reaction to prepare dibenzalacetone from 5.3 g benzaldehyde, a total of 3.51 g of product was obtained. The percentage yield in this reaction was _____.