List of top Chemistry Questions asked in JEE Main

Fig.

Considering the above reactions, the compound ‘A’ and compound ‘B’ respectively are :

Consider the above reaction, the compound ‘A’ is :

Fig.
Which among the following pairs has only herbicides?
‘x’ g of molecular oxygen (O2) is mixed with 200 g of neon (Ne). The total pressure of the non-reactive mixture of O2 and Ne in the cylinder is 25 bar. The partial pressure of Ne is 20 bar at the same temperature and volume. The value of ‘x’ is ___.
[Given : Molar mass of O2 = 32 g mol–1 and Molar mass of Ne = 20 g mol–1]
1.80 g of solute A was dissolved in 62.5 cm3 of ethanol and freezing point of the solution was found to be 155.1 K. The molar mass of solute A is ____ g mol–1.
[Given : Freezing point of ethanol is 156.0 K, Density of ethanol is 0.80 g cm–3, Freezing point depression constant of ethanol is 2.00 K kg mol–1]
For a cell, \(Cu(s)|Cu^{2+}(0.001M)||Ag^+(0.01M)|Ag(s)\)
the cell potential is found to be \(0.43 V\) at \(298 K\). The magnitude of standard electrode potential for \(Cu^{2+}/{Cu}\) is ____ \(× 10^{–2}\) V.
[Given: \(E_{Ag^+/Ag^⊖}=0.80\) V and \(\frac {2.303RT}{F}=0.06 V\)]
The reaction of zinc with excess of aqueous alkali, evolves hydrogen gas and gives:
A 10 g mixture of hydrogen and helium is contained in a vessel of capacity 0.0125 m3 at 6 bar and 27°C. The mass of helium in the mixture is _______ g. (nearest integer)
Given : R = 8.3 J K–1 mol–1
(Atomic masses of H and He are 1 u and 4 u, respectively)
The vapour pressures of two volatile liquids A and B at 25°C are 50 Torr and 100 Torr, respectively. If the liquid mixture, contains 0.3 mole fraction of A, then the mole fraction of liquid B in the vapour phase is \(\frac {x}{17}\). The value of x is _____.
\(250\) \(g\) solution of \(D-glucose\) in water contains 10.8% of carbon by weight. The molality of the solution is nearest to (Given: Atomic Weights are, \(H, 1 u; C, 12 u; O, 16 u\))
The limiting molar conductivities of \(NaI\), \(NaNO_3\) and \(AgNO_3\) are \(12.7\), \(12.0\) and \(13.3\) mS m2 mol–1, respectively (all at 25°C). The limiting molar conductivity of \(AgI\) at this temperature is ____ mS m2 mol–1.
A rigid nitrogen tank stored inside a laboratory has a pressure of 30 atm at 06:00 am when the temperature is 27°C. At 03:00 pm, when the temperature is 45°C, the pressure in the tank will be _______ atm. [nearest integer]
Given below are two statements :
Statement-I : For KI, molar conductivity increases steeply with dilution.
Statement-II : For carbonic acid, molar conductivity increases slowly with dilution.
In the light of the above statements, choose the correct answer from the options given below :
If the solubility product of PbS is 8 × 10–28, then the solubility of PbS in pure water at 298 K is x × 10–16 mol L–1. The value of x is ________. (Nearest integer)
[given : \(\sqrt2=1.41\)]
Class XII students were asked to prepare one litre of buffer solution of pH \(8.26\) by their Chemistry teacher. The amount of ammonium chloride to be dissolved by the student in \(0.2\) M ammonia solution to make one litre of the buffer is (Given : \(pK_b\) \((NH_3)\) = \(4.74\), Molar mass of \(NH_3\) = \(17\) g \(mol^{–1}\), Molar mass of \(NH_4Cl\) = \(53.5\) \(g\) \(mol^{–1}\))
Consider the following set of quantum numbers.
\(n \,|\, m_|\)
A. 3 3 –3
B. 3 2 –2
C. 2 1 +1
D. 2 2 +2
The number of correct sets of quantum numbers is _____.
The correct stability order of the following diazonium salt is
correct stability order of the diazonium salt
Given below are two statements.
Statement I: The presence of weaker π-bonds make alkenes less stable than alkanes.
Statement II: The strength of the double bond is greater than that of carbon-carbon single bond.
In the light of the above statements, choose the correct answer from the options given below.

Match List-I with List-II.

List-I (Metal) 

 

 

List-II (Emitted light

 

wavelength (nm))

(A) Li (I) 670.8
(B) Na (II) 589.2
(C) Rb (III) 780.0
(D) Cs (IV) 455.5

Choose the most appropriate answer from the options given below:

2 L of 0.2 M \(H_2SO_4\) is reacted with 2 L of 0.1 M NaOH solution, the molarity of the resulting product \(Na_2SO_4\) in the solution is _______ millimolar. (Nearest integer)
Total number of isomers (including stereoisomers) obtained on monochlorination of methylcyclohexane is____.
A 0.5 percent solution of potassium chloride was found to freeze at –0.24°C. The percentage dissociation of potassium chloride is ______. (Nearest integer)
(Molal depression constant for water is 1.80 K kg mol–1 and 
molar mass of KCl is 74.6 g mol–1)
In neutral or alkaline solution, MnO4– oxidises thiosulphateto :

On complete combustion 0.30 g of an organic compound gave 0.20 g of carbon dioxide and 0.10 g of water. The percentage of carbon in the given organic compound is ______. (Nearest Integer)

Given below are two statements:
Statement I: On heating with KHSO4, glycerol is dehydrated and acrolein is formed.
Statement II: Acrolein has fruity odour and can be used to test glycerol’s presence.
Choose the correct option