List of top Questions asked in JEE Main

Data given for the following reaction is as follows: 
FeO(s) + C(graphite) \(\rightarrow\) Fe(s) + CO(g) 
The minimum temperature in K at which the reaction becomes spontaneous is _________. (Integer answer) 

 

The incorrect expression among the following is :
Five moles of an ideal gas at 293 K is expanded isothermally from an initial pressure of 2.1 MPa to 1.3 MPa against at constant external pressure 4.3 MPa. The heat transferred in this process is ________ kJ mol⁻¹. (Rounded-off to the nearest integer) [Use R=8.314 J mol⁻¹K⁻¹]

For water at 100$^\circ$C and 1 bar, 
(Round off to the Nearest Integer) 
[Use : R=8.31 J mol$^{-1}$ K$^{-1}$] 
[Assume volume of H$\_2$O(l) is much smaller than volume of H$\_2$O(g). Assume H$\_2$O(g) can be treated as an ideal gas] 
 

The reaction of cyanamide, NH$_2$CN(s), with oxygen was run in a bomb calorimeter and $\Delta U$ was found to be -742.24 kJ mol$^{-1}$. The magnitude of $\Delta H_{298}$ for the reaction NH$_2$CN(s) + 3/2 O$_2$(g) $\rightarrow$ N$_2$(g) + CO$_2$(g) + H$_2$O(l) is _________ kJ.
For the reaction $A_{(g)} \rightleftharpoons B_{(g)}$, the value of the equilibrium constant at 300 K and 1 atm is equal to 100.0. The value of $\Delta_r G^\circ$ for the reaction at 300 K and 1 atm in J mol$^{-1}$ is $-xR$, where $x$ is __________. (Rounded off to the nearest integer) [R=8.31 J mol$^{-1}K^{-1}$ and $\ln 10=2.3$]
When 400 mL of 0.2 M H$_2$SO$_4$ solution is mixed with 600 mL of 0.1 M NaOH solution, the increase in temperature of the final solution is ________ $\times 10^{-2}$ K. (Round off to the Nearest Integer).
[Use : H$^+$(aq) + OH$^-$(aq) $\rightarrow$ H$_2$O(l) ; $\Delta_r H$ = -57.1 kJ mol$^{-1}$
Specific heat of H$_2$O = 4.18 J K$^{-1}$ g$^{-1}$
density of H$_2$O = 1.0 g cm$^{-3}$
Assume no change in volume of solution on mixing.]
At 298 K, the enthalpy of fusion of a solid (X) is 2.8 kJ \(mol^{-1}\) and the enthalpy of vaporisation of the liquid (X) is 98.2 kJ \(mol^{-1}\). The enthalpy of sublimation of the substance (X) in kJ \(mol^{-1}\) is ________. (in nearest integer)
For the reaction C₂H₆ → C₂H₄ + H₂ the reaction enthalpy ΔH = _________ kJ mol$^{-1}$. (Round off to the Nearest Integer). [Given : Bond enthalpies in kJ mol$^{-1}$ : C-C : 347, C=C : 611; C-H : 414, H-H : 436]
Assuming ideal behaviour, the magnitude of log K for the following reaction at 25 °C is \( x \times 10^{-1} \). The value of \( x \) is __________ . (Integer answer) \( 3\,\text{HC}\equiv\text{CH (g)} \rightleftharpoons \text{C}_6\text{H}_6 \text{ (l)} \) [Given : \( \Delta_f G^\circ (\text{HC}\equiv\text{CH}) = -2.04 \times 10^5 \,\text{J mol}^{-1} \); \( \Delta_f G^\circ (\text{C}_6\text{H}_6) = -1.24 \times 10^5 \,\text{J mol}^{-1} \); \( R = 8.314 \,\text{J K}^{-1} \text{ mol}^{-1} \)]
The bond order and magnetic behaviour of O\(_2^-\) ion are, respectively :
\(AB_3\) is an interhalogen T-shaped molecule. The number of lone pairs of electrons on A is _________. (Integer answer)

Match List - I with List - II : 

Choose the most appropriate answer from the options given below : 
 

The compound/s which will show significant intermolecular H-bonding is/are : 

 

The number of species having non-pyramidal shape among the following is _________.
(A) SO\(_3\)
(B) NO\(_3^-\)
(C) PCl\(_3\)
(D) CO\(_3^{2-}\)

The number of hydrogen bonded water molecule(s) associated with stoichiometry \( CuSO_4 \cdot 5H_2O \) is ____________
 

According to molecular orbital theory, the number of unpaired electron(s) in $\text{O}_2^{2-}$ is ________.
Which among the following species has unequal bond lengths?
Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A : Lithium halides are some what covalent in nature.
Reason R : Lithium possess high polarisation capability.
In the light of the above statements, choose the most appropriate answer from the options given below :
The difference between bond orders of CO and NO$^\oplus$ is $\frac{x}{2}$ where x = _________. (Round off to the Nearest Integer)
In gaseous triethyl amine the "-C-N-C-" bond angle is _________ degree.
According to molecular orbital theory, the species among the following that does not exist is :
The ionization enthalpy of Na$^+$ formation is 495.8, electron gain enthalpy of Br is -325.0, and lattice enthalpy of NaBr is -728.4 kJ mol$^{-1}$. The energy for the formation of NaBr ionic solid is (-) __________ $\times 10^{-1}$ kJ mol$^{-1}$.
Which of the following are isostructural pairs ? (Note: Based on typical JEE pairs like $SO_4^{2-}$ and $BF_4^-$ or $NH_3$ and $PH_3$)
The number of species below that have two lone pairs of electrons in their central atom is _________. (Round off to the Nearest Integer). SF₄, BF₄⁻, ClF₃, AsF₃, PCl₅, BrF₅, XeF₄, SF₆