List of top Chemistry Questions asked in JEE Main

When Ethane-1,2-diamine is added progressively to an aqueous solution of Nickel (II) chloride, the sequence of colour change observed will be:

Consider ‘n’ is the number of lone pair of electrons present in the equatorial position of the most stable structure of $ \text{ClF}_3 $. The ions from the following with ‘n’ number of unpaired electrons are:
A. $ \text{V}^{3+} $
B. $ \text{Ti}^{3+} $
C. $ \text{Cu}^{2+} $
D. $ \text{Ni}^{2+} $
E. $ \text{Ti}^{2+} $
Choose the correct answer from the options given below:

Match List - I with List - II.

Ice at $ -5^\circ C $ is heated to become vapor with temperature of $ 110^\circ C $ at atmospheric pressure. The entropy change associated with this process can be obtained from:

Ice and water are placed in a closed container at a pressure of 1 atm and temperature 273.15K. If pressure of the system is increased 2 times, keeping temperature constant, then identify correct observation from the following:

The molarity of a 70%(mass/mass) aqueous solution of a monobasic acid (X) is:

The incorrect decreasing order of atomic radii is:

For hydrogen atom, the orbital/s with lowest energy is/are:

In the given structure, number of $ sp $ and $ sp^2 $ hybridized carbon atoms present respectively are:

For the reaction:

The correct order of set of reagents for the above conversion is :

Which of the following mixing of 1M base and 1M acid leads to the largest increase in temperature?

The molecules having square pyramidal geometry are:

If \[ \text{C(diamond)} \rightarrow \text{C(graphite)} + X \, \text{kj mol}^{-1} \] \[ \text{C(diamond)} + \text{O}_2(g) \rightarrow \text{CO}(g) + Y \, \text{kj mol}^{-1} \] \[ \text{C(graphite)} + \text{O}_2(g) \rightarrow \text{CO}(g) + Z \, \text{kj mol}^{-1} \] At constant temperature. Then:

The formation enthalpies, $ \Delta H_f^\circ $ for $ \text{H}_2 $ and $ \text{O}_2 $ are 220.0 and 250.0 kJ mol$^{-1}$, respectively, at 298.15 K, and $ \Delta H_f^\circ $ for $ \text{H}_2\text{O} $ (g) is -242.0 kJ mol$^{-1}$ at the same temperature. The average bond enthalpy of the O-H bond in water at 298.15 K is:

Which of the following statement(s) is correct for the adiabatic process?

500 J of energy is transferred as heat to 0.5 mol of Argon gas at 298 K and 1.00 atm. The final temperature and the change in internal energy respectively are: Given $ R = 8.3 \, \text{J K}^{-1} \text{mol}^{-1} $.

A perfect gas (0.1 mol) having $ \bar{C}_V = 1.50 $ R (independent of temperature) undergoes the above transformation from point 1 to point 4. If each step is reversible, the total work done (w) while going from point 1 to point 4 is ____ J (nearest integer) [Given : R = 0.082 L atm K$^{-1}$]

A sample of n-octane (1.14 g) was completely burnt in excess of oxygen in a bomb calorimeter, whose heat capacity is 5 kJ K$^{-1}$. As a result of combustion, the temperature of the calorimeter increased by 5 K. The magnitude of the heat of combustion at constant volume is ___

Given below are two statements : Statement I : When a system containing ice in equilibrium with water (liquid) is heated, heat is absorbed by the system and there is no change in the temperature of the system until whole ice gets melted. Statement II : At melting point of ice, there is absorption of heat in order to overcome intermolecular forces of attraction within the molecules of water in ice and kinetic energy of molecules is not increased at melting point. In the light of the above statements, choose the correct answer from the options given below:

Consider the given data: $$ \text{(a) HCl(g) + 10H}_2\text{O(l)} \rightarrow \text{HCl.10} \text{ H}_2\text{O} \quad \Delta H = -69.01 \, \text{kJ/mol}^{-1} $$ $$ \text{(b) HCl(g) + 40H}_2\text{O(l)} \rightarrow \text{HCl.40} \text{ H}_2\text{O} \quad \Delta H = -72.79 \, \text{kJ/mol}^{-1} $$ Choose the correct statement:

The formation enthalpies, $ \Delta H_f^\circ $ for $ \text{H}_2 $ and $ \text{O}_2 $ are 220.0 and 250.0 kJ mol$^{-1}$, respectively, at 298.15 K, and $ \Delta H_f^\circ $ for $ \text{H}_2\text{O} $ (g) is -242.0 kJ mol$^{-1}$ at the same temperature. The average bond enthalpy of the O-H bond in water at 298.15 K is:

The correct statement amongst the following is :

Which of the following compounds exhibits ionic bonding?

A group 15 element forms $ d\pi - d\pi $ bond with transition metals. It also forms a hydride, which is the strongest base among the hydrides of other group members that form $ d\pi - d\pi $ bonds. The atomic number of the element is ________________________.

The number of molecules/ions that show linear geometry among the following is _____. SO₂, BeCl₂, CO₂, N₃⁻, NO₂, F₂O, XeF₂, NO₂⁺, I₃⁻, O₃