List of top Chemistry Questions asked in JEE Main

For the first order reaction $A \rightarrow B$, the half life is $30 min$ The time taken for $75 \%$ completion of the reaction is min (Nearest integer) Given : $\log _g 2=03010$ $ \log 3=04771 $ $ \log 5=06989$
An organic compound undergoes first order decomposition If the time taken for the \(60 \%\) decomposition is \(540 \,s\), then the time required for \(90 \%\) decomposition will be is ______ s. (Nearest integer)
(Given: \(\ln 10=2.3 ; \log 2=0.3\))
The number of correct statement/s from the following is
A. Larger the activation energy, smaller is the value of the rate constant
B. The higher is the activation energy, higher is the value of the temperature coefficient 
C. At lower temperatures, increase in temperature causes more change in the value of $k$ than at higher temperature 
D. A plot of $\ln k$ vs $\frac{1}{T}$ is a straight line with slope equal to $-\frac{E_a}{R}$
'$A$' in the given reaction is
Which of the following conformations will be the most stable?
How many statements are correct:
  1. If there is no relation between rate constant and temperature, then activation energy is negative.
  2. If the activation energy is zero, rate constant is temperature independent.
  3. If rate constant increases with increase of temperature, activation energy is positive.
  4. If rate constant decreases with increase in temperature, activation energy is negative.
Select the correct option:
\(2CO (g) + O_2 (g) → 2CO_2 (g) ; ΔH = -x KJ/mol\)
\(C (graphite) + O_2(g) → CO_2 (g) ; AH = -y KJ/mol\)
Then AH for, \(C(graphite) + \frac{1}{2} O_2 (g) → CO (g):\)
The enthalpy change for the conversion of \(\frac{1}{2} Cl_2(g)\) to \(Cl^{-}(aq)\) is (-)_____________ \(KJ mol^{-1}\) (Nearest integer)
Given : \(\Delta_{\text {dis }} H _{ Cl _{2( g )}}^{\ominus}=240\, kJ \,mol ^{-1}\), \(\Delta_{ eg } H _{ Cl }^{\ominus}=-350\, kJ \,mol ^{-1}\), \(\Delta_{\text {hyd }} H ^\theta Cl _{( g )}^{-}=-380 \,kJ \,mol ^{-1}\)

The value of \(log_{10}K\) for a reaction A ⇋ B is

(Given,

 \(\Delta H^{\circ}_{298K}\) = –54.67 kJ \(mol^{-1}\)

 \(\Delta H^{\circ}_{298K}\) = 10 kJ \(mol^{-1}\)

 and R = 8.314 J \(K^{-1}mol^{-1}\)

 2.303 × 8.314 × 298 = 5705) 

The density of $3 M$ solution of $NaCl$ is $10 \,g \,mL -1$ Molality of the solution is _______ $\times 10^{-2} m$ (Nearest integer) Given: Molar mass of Na and $Cl$ is $23$ and $355 \,g \,mol ^{-1}$ respectively
Which transition in the hydrogen spectrum would have the same wavelength as the Balmer type transition from $n =4$ to $n =2$ of $He ^{+}$spectrum

Oxidation number of Mo in Ammonophosphomolybdate

The major product P formed in the given reaction is:
The major product P formed
Match List I with List II :
LIST I Isomeric pairsLIST II Type of isomers
APropanamine and N-MethylethanamineIMetamers
BHexan-2-one and Hexan-3-oneII
Positional isomers
CEthanamide and HydroxyethanimineII
Functional isomers
Do-nitrophenol and p-nitrophenolIVTautomers
Choose the correct answer from the options given below:
Given below are two statements Statement I : Pig iron is obtained by heating cast iron with scrap iron Statement II : Pig iron has a relatively lower carbon content than that of cast iron In the light of the above statements, choose the correct answer from the options given below
The resistivity of a $0.8 M$ solution of an electrolyte is $5 \times 10^{-3} \Omega cm$ Its molar conductivity is ____ $\times 10^4\, \Omega^{-1}\, cm ^2 \,mol ^{-1}$

\(Pt(s) ∣ H2​(g)(1atm) ∣ H+(aq, [H+]=1)\, ∥\, Fe3+(aq), Fe2+(aq) ∣ Pt(s)\)
Given\( E^∘_{Fe^{3+}Fe^{2+}}\)\(=0.771V\) and \(E^∘_{H^{+1/2}H_2}​=0\,V,T=298K\)
If the potential of the cell is 0.712V, the ratio of concentration of \(Fe2+\) to \(Fe3+\) is

If wavelength of the first line of the Paschen series of hydrogen atom is _____ nm, then the wavelength of the second line of this series is nm (Nearest integer)
Lead storage battery contains $38 \%$ by weight solution of $H _2 SO _4$ The van't Hoff factor is $2.67$ at this concentration The temperature in Kelvin at which the solution in the battery will freeze is ______(Nearest integer) Given $K _f=1.8\, K \,kg\, mol ^{-1}$
Find out the major product for the following reaction.
Find out the major product for the following reaction.
The electrode potential of the following half cell at $298\, K$ $X \left| X ^{2+}(0.001 M ) \| Y ^{2+}(0.01 M )\right| Y$ is _____$\times 10^{-2} V$ (Nearest integer)
 Given: $E _{ x ^{2 *} \mid x }^0=-2.36\, V$ 
$ E _{ Y ^{0-1 Y }}^0=+0.36\, V$ 
$\frac{2303 RT }{ F }=0.06 \,V$
For independent processes at 300K
ProcessΔH/kJmol−1ΔS/JK−1
A-25-80
B-2240
C25-50
D2220

The number of non-spontaneous processes from the following is
The d-electronic configuration of $\left[ CoCl _4\right]^{2-}$ in tetrahedral crystal field is $e ^{ m } t _2 ^n$ Sum of "$m$" and "number of unpaired electrons" is
How many of the following metal ions have similar value of spin only magnetic moment in gaseous state? (Given: Atomic number: $V, 23; Cr, 24; Fe, 26; Ni, 28$) $V ^{3+} \cdot Ci ^{3+} \cdot Fe ^{2+} \cdot Ni ^{3+}$
For $OF _2$ molecule consider the following : A Number of lone pairs on oxygen is 2 B FOF angle is less than $1045^{\circ}$ C Oxidation state of $O$ is $-2$ D Molecule is bent ' $V$ ' shaped E Molecular geometry is linear correct options are: