List of top Chemistry Questions asked in JEE Main

The incorrect relationship in the following pairs in relation to ionisation enthalpies is:

The spin-only magnetic moment ($\mu$) value (B.M.) of the compound with the strongest oxidising power among $Mn_2O_3$, $TiO$, and $VO$ is ________________________ B.M. (Nearest integer).

Atomic number of element with lowest first ionisation enthalpy is:

Assume a living cell with 0.9%($w/w$) of glucose solution (aqueous). This cell is immersed in another solution having equal mole fraction of glucose and water. (Consider the data up to first decimal place only) The cell will:

Statement-I: Melting point of neopentane is greater than that of n-pentane.
Statement-II: Neopentane gives only one mono-substituted product.

0.5 g of an organic compound gives 1.46 g CO$_2$ and 0.9 g H$_2$O. Find the percentage composition of carbon.

Identify correct conversion during acidic hydrolysis from the following: (A) Starch gives galactose.
(B) Cane sugar gives equal amount of glucose and fructose.
(C) Milk sugar gives glucose and galactose.
(D) Amylopectin gives glucose and fructose.
(E) Amylose gives only glucose.
Choose the correct answer from the options given below:

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

Choose the correct set of reagents for the following conversion:

The number of species from the following that are involved in $ sp^3d^2 $ hybridization is $ \text{[Co(NH}_3\text{)}_6\text{]}^{3+}, \text{SF}_6, \text{[CrF}_6\text{]}^{3-}, \text{[CoF}_6\text{]}^{3-}, \text{[Mn(CN)}_6\text{]}^{3-} $ and $ \text{[MnCl}_6\text{]}^{3-} $

Correct statements for an element with atomic number 9 are
A. There can be 5 electrons for which $ m_s = +\frac{1}{2} $ and 4 electrons for which $ m_s = -\frac{1}{2} $
B. There is only one electron in $ p_z $ orbital.
C. The last electron goes to orbital with $ n = 2 $ and $ l = 1 $.
D. The sum of angular nodes of all the atomic orbitals is 1.
Choose the correct answer from the options given below:

Match the LIST-I with LIST-II

Choose the correct answer from the options given below:

In a first order decomposition reaction, the time taken for the decomposition of reactant to one fourth and one eighth of its initial concentration are $ t_1 $ and $ t_2 $ (s), respectively. The ratio $ t_1 / t_2 $ will be:

Match the LIST-I with LIST-II

Choose the correct answer from the options given below:

HA $ (aq) \rightleftharpoons H^+ (aq) + A^- (aq) $ The freezing point depression of a 0.1 m aqueous solution of a monobasic weak acid HA is 0.20 °C. The dissociation constant for the acid is Given: $ K_f(H_2O) = 1.8 \, \text{K kg mol}^{-1} $, molality ≡ molarity

On combustion 0.210 g of an organic compound containing C, H and O gave 0.127 g $ \text{H}_2\text{O} $ and 0.307 g $ \text{CO}_2 $. The percentages of hydrogen and oxygen in the given organic compound respectively are:

Given below are two statements:
Statement I: A homoleptic octahedral complex, formed using monodentate ligands, will not show stereoisomerism
Statement II: cis- and trans-platin are heteroleptic complexes of Pd.
In the light of the above statements, choose the correct answer from the options given below

Match the LIST-I with LIST-II

Choose the correct answer from the options given below:

Given below are two statements:
Statement I: $ H_2Se $ is more acidic than $ H_2Te $
Statement II: $ H_2Se $ has higher bond enthalpy for dissociation than $ H_2Te $
In the light of the above statements, choose the correct answer from the options given below.

20 mL of sodium iodide solution gave 4.74 g silver iodide when treated with excess of silver nitrate solution. The molarity of the sodium iodide solution is _____ M. (Nearest Integer value) (Given : Na = 23, I = 127, Ag = 108, N = 14, O = 16 g mol$^{-1}$)

The equilibrium constant for decomposition of $ H_2O $ (g) $ H_2O(g) \rightleftharpoons H_2(g) + \frac{1}{2} O_2(g) \quad (\Delta G^\circ = 92.34 \, \text{kJ mol}^{-1}) $ is $ 8.0 \times 10^{-3} $ at 2300 K and total pressure at equilibrium is 1 bar. Under this condition, the degree of dissociation ($ \alpha $) of water is _____ $\times 10^{-2}$ (nearest integer value). [Assume $ \alpha $ is negligible with respect to 1]

Resonance in X$_2$Y can be represented as

The enthalpy of formation of X$_2$Y is 80 kJ mol$^{-1}$, and the magnitude of resonance energy of X$_2$Y is:

The energy of an electron in first Bohr orbit of H-atom is $-13.6$ eV. The magnitude of energy value of electron in the first excited state of Be$^{3+}$ is _____ eV (nearest integer value)

Consider the following half cell reaction $ \text{Cr}_2\text{O}_7^{2-} (\text{aq}) + 6\text{e}^- + 14\text{H}^+ (\text{aq}) \longrightarrow 2\text{Cr}^{3+} (\text{aq}) + 7\text{H}_2\text{O}(1) $
The reaction was conducted with the ratio of $\frac{[\text{Cr}^{3+}]^2}{[\text{Cr}_2\text{O}_7^{2-}]} = 10^{-6}$
The pH value at which the EMF of the half cell will become zero is ____ (nearest integer value)
[Given : standard half cell reduction potential $\text{E}^\circ_{\text{Cr}_2\text{O}_7^{2-}, \text{H}^+/\text{Cr}^{3+}} = 1.33\text{V}, \quad \frac{2.303\text{RT}}{\text{F}} = 0.059\text{V}$