List of top Chemistry Questions asked in JEE Main

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)

20 mL of 0.02 M hypo solution is used for the titration of 10 mL of copper sulphate solution, in the presence of excess of KI using starch as an indicator. The molarity of \(Cu^{2+}\) is found to be ________ × \(10^{–2} M\). [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 :
The pressure of a moist gas at 27°C is 4 atm. The volume of the container is doubled at the same temperature. The new pressure of the moist gas is ______ ×10–1 atm. (Nearest integer)(Given: The vapor pressure of water at 27°C is 0.4 atm.)

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
Chlorophyll extracted from the crushed green leaves was dissolved in water to make 2 L solution of Mg of concentration 48 ppm. The number of atoms of Mg in this solution is \(x × 10^{20}\) atoms. The value of \(x\) is ________. (Nearest integer)
(Given : Atomic mass of Mg is 24 g mol–1; NA = 6.02 × 1023 mol–1)
[Fe(CN)6]4–
[Fe(CN)6]3–
[Ti(CN)6]3–
[Ni(CN)4]2–
[Co(CN)6]3–
Among the given complexes, number of paramagnetic complexes is_______.
40% of HI undergoes decomposition to H2 and I2 at 300 K. ΔG° for this decomposition reaction at one atmosphere pressure is _____ J mol–1. [nearest integer]
(Use R = 8.31 J K–1 mol–1; log 2 = 0.3010, ln 10 = 2.3, log 3 = 0.477)
0.01 M KMnO4 solution was added to 20.0 mL of 0.05 M Mohr’s salt solution through a burette. The initial reading of 50 mL burette is zero. The volume of KMnO4 solution left in burette after the end point is _____ml. [nearest integer]
For a given chemical reaction
\(γ_1A + γ_2B → γ_3C + γ_4D\)
Concentration of C changes from 10 mmol dm–3 to 20 mmol dm–3 in 10 seconds. Rate of appearance of D is 1.5 times the rate of disappearance of B which is twice the rate of disappearance A. The rate of appearance of D has been experimentally determined to be 9 mmol dm–3 s–1. Therefore, the rate of reaction is _____ mmol dm–3 s–1. (Nearest Integer)
20 mL of 0.1 M NH4OH is mixed with 40 mL of 0.05 M HCl.The pH of the mixture is nearest to:(Given: Kb(NH4OH) = 1 × 10–5 ,log 2 = 0.30,log 3 = 0.48, log 5 = 0.69, log 7 = 0.84, log 11 =1.04)
Which of the following pair of molecules contain odd electron molecule and an expanded octet molecule?
\(2NOCl(g) ⇌ 2NO(g) + Cl_2(g)\)
In an experiment, \(2.0\) moles of \(NOCl\) was placed in a one-litre flask and the concentration of \(NO\) after equilibrium established, was found to be \(0.4\) mol/ L. The equilibrium constant at \(30°C\) is ____ \(×10^{–4}\).