List of top Chemistry Questions asked in JEE Main

Sodium oxide reacts with water to produce sodium hydroxide. 20.0 g of sodium oxide is dissolved in 500 mL of water. Neglecting the change in volume, the concentration of the resulting NaOH solution is ________ $\times 10^{-1}$ M. (Nearest integer) [Atomic mass : Na = 23.0, O = 16.0, H = 1.0]
The empirical formula for a compound with a cubic close packed arrangement of anions and with cations occupying all the octahedral sites is $A_x B$. The value of $x$ is ________. (Integer answer)
The value of magnetic quantum number of the outermost electron of $\text{Zn}^+$ ion is ________. (Integer answer)
According to molecular orbital theory, the number of unpaired electron(s) in $\text{O}_2^{2-}$ is ________.
1.22 g of an organic acid is separately dissolved in 100 g of benzene ($K_b = 2.6 \text{ K kg mol}^{-1}$) and 100 g of acetone ($K_b = 1.7 \text{ K kg mol}^{-1}$). The acid is known to dimerize in benzene but remain as a monomer in acetone. The boiling point of the solution in acetone increases by $0.17^\circ\text{C}$. The increase in boiling point of solution in benzene in $^\circ\text{C}$ is $x \times 10^{-2}$. The value of $x$ is ________. (Nearest integer) [Atomic mass : C = 12.0, H = 1.0, O = 16.0]
The pH of a solution obtained by mixing 50 mL of 1 M HCl and 30 mL of 1 M NaOH is $x \times 10^{-1}$. The value of $x$ is ________. (Nearest integer) [log 2.5 = 0.3979]
For the reaction $\text{A} \to \text{B}$, the rate constant $k$ (in $\text{s}^{-1}$) is given by $\log_{10} k = 20.35 - \frac{2.47 \times 10^3}{\text{T}}$. The energy of activation in $\text{kJ mol}^{-1}$ is ________. (Nearest integer) [Given : R = 8.314 J K$^{-1}$ mol$^{-1}$]
$\text{CH}_4$ is adsorbed on 1 g charcoal at $0^\circ\text{C}$ following the Freundlich adsorption isotherm. 10.0 mL of $\text{CH}_4$ is adsorbed at 100 mm of Hg, whereas 15.0 mL is adsorbed at 200 mm of Hg. The volume of $\text{CH}_4$ adsorbed at 300 mm of Hg is $10^x$ mL. The value of $x$ is ________ $\times 10^{-2}$. (Nearest integer) [Use $\log_{10} 2 = 0.3010, \log_{10} 3 = 0.4771$]
In the electrolytic refining of blister copper, the total number of main impurities, from the following, removed as anode mud is ________.
Pb, Sb, Se, Te, Ru, Ag, Au and Pt.
The transformation occurring in Duma's method is given below:
$\text{C}_2 \text{H}_7 \text{N} + (2x + y/2) \text{CuO} \to x \text{CO}_2 + y/2 \text{H}_2\text{O} + z/2 \text{N}_2 + (2x + y/2) \text{Cu}$.
The value of $y$ is ________. (Integer answer)
Which among the following species has unequal bond lengths?
The solubility of Ca(OH)$_2$ in water is:
[Given: The solubility product of Ca(OH)$_2$ in water = 5.5 $\times$ 10⁻⁶]
Which one of the following statements is FALSE for hydrophilic sols?
The correct order of bond dissociation enthalpy is:
The method used for the purification of Indium is:
The set of elements that are used in the fabrication of transistors is:
In which of the following order the given complex ions are arranged correctly with respect to their decreasing spin only magnetic moment?
(i) [FeF$_6$]$^{3-}$ (ii) [Co(NH$_3$)$_6$]$^{3+}$ (iii) [NiCl$_4$]$^{2-}$ (iv) [Cu(NH$_3$)$_4$]$^{2+}$
Which of the following compound is added to the sodium extract before addition of silver nitrate for testing of halogens?

The major product of the following reaction is : 
(Image shows Benzene reacting with 2-nitropropene in presence of H$_2$SO$_4$) 

The correct order of acid character of the following compounds is : 
I: Phenol, II: p-Nitrobenzoic acid, III: Benzoic acid, IV: p-Toluic acid 

What is 'X' in the given reaction?
CH$_2$OH—CH$_2$OH + oxalic acid $\xrightarrow{210^\circ\text{C}}$ X (major product)

Correct statement about the given chemical reaction is : 

Carbylamine test is used to detect the presence of primary amino group in an organic compound. Which of the following compound is formed when this test is performed with aniline ?

Which of the following is correct structure of $\alpha$-anomer of maltose? 

Given below are two statements:
Statement I: The identification of Ni$^{2+}$ is carried out by dimethyl glyoxime in the presence of NH$_4$OH.
Statement II: The dimethyl glyoxime is a bidentate neutral ligand.