List of top Chemistry Questions asked in JEE Main

The number of incorrect statements from the following is _____
A. The electrical work that a reaction can perform at constant pressure and temperature is equal to the reaction Gibbs energy.
B. E°_cell is dependent on the pressure.
C. dE^θ cell/dT = Δ_rS^θ/nF
D. A cell is operating reversibly if the cell potential is exactly balanced by an opposing source of potential difference.

For complete combustion of ethene,
\(C_2H_4(g) + 3O_2(g) \longrightarrow 2CO_2(g) + 2H_2O (l)\)
the amount of heat produced as measured in bomb calorimeter is 1406 kJ mol^-1 at 300K. The minimum value of \(T\Delta S\) needed to reach equilibrium is (-) _____ . kJ.(Nearest integer)
Given: R = 8.3 J K^-1 mol^-1

Given below are two statements:
Statement I: In redox titration, the indicators used are sensitive to change in pH of the solution.
Statement II: In acid-base titration, the indicators used are sensitive to change in oxidation potential.
In the light of the above statements, choose the most appropriate answer from the options given below

Match List l with List ll.

List I Natural amino acid	List II One letter code
(I) Glutamic acid	(a) Q
(II) Glutamine	(b) W
(III) Tyrosine	(c) E
(IV) Tryptophan	(d) Y

Choose the correct answer from the options given below:

At constant temperature, a gas is at a pressure of 940.3 mm Hg. The pressure at which its volume decreases by 40% is mm Hg. (Nearest integer)

The descending order of acidity for the following carboxylic acid is-
A. CH₃COOH
B. F₃C-COOH
C. CICH₂-COOH
D. FCH₂-COOH
E. BrCH₂-COOH
Choose the correct answer from the options given below:

The correct order of reactivity of following haloarenes towards nucleophilic substitution with aqueous NaOH is 

Choose the correct answer from the options given below:

The correct IUPAC nomenclature for the following compound is.

The number of bent-shaped molecule(s) from the following is_______? 
SO₂, O₃, I₃^-, N₃^-

The Sum of number of lone pairs in central atom in IF₅ and IF₇ is:

Which of these reactions is not a part of breakdown of ozone in stratosphere?

Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R
Assertion A : Sodium is about 30 times as abundant as potassium in the oceans.
Reason R : Potassium is bigger in size than sodium.
In the light of the above statements, choose the correct answer from the options given below

Henry Moseley studied characteristic X-ray spectra of elements. The graph which represents his observation correctly is
Given v = frequency of X-ray emitted
Z = atomic number

Arrange the following gases in increasing order of van der Waals constant 'a'
A. Ar
B. CH4
C. H₂O
D. C6H6
Choose the correct option from the following.

Identify the correct order of reactivity for the following pairs towards the respective mechanism




Choose the correct answer from the options given below :

Molar mass of the hydrocarbon (X) which on ozonolysis consumes one mole of O3 per mole of (X) and gives one mole each of ethanal and propanone is _______ g mol-1  
(Molar mass of C : 12 g mol-1 , H : 1 g mol-1)

The titration curve of weak acid vs. strong base with phenolphthalein as indictor is shown below. The K_{phenolphthalein} = 4 × 10^-10 . 
Given: log2 = 0.3

The number of following statements which is/are correct about phenolphthalein is______
A. It can be used as an indicator for the titration of weak acid with weak base.
B. It begins to change colour at pH = 8.4
C. It is a weak organic base
D. It is colourless in acidic medium.

The number of following statement/s which is/are\(\text{\underline{ incorrect}}\) is______  
(A) Line emission spectra are used to study the electronic structure  
(B) The emission spectra of atoms in the gas phase show a continuous spread of wavelength from red to violet  
(C) An absorption spectrum is like the photographic negative of an emission spectrum  
(D) The element helium was discovered in the sun by spectroscopic method.

Three bulbs are filled with CH4, CO2 and Ne as shown in the picture. The bulbs are connected through pipes of zero volume. When the stopcocks are opened and the temperature is kept constant throughout, the pressure of the system is found to be_______atm. (Nearest integer)

In chromyl chloride, the number of d-electrons present on chromium is same as in (Given at no. of Ti : 22, V : 23, Cr : 24, Mn : 25, Fe : 26)

20 mL of calcium hydroxide was consumed when it was reacted with 10 mL of unknown solution of H₂SO4. Also 20 mL standard solution of 0.5 M HCI containing 2 drops of phenolphthalein was titrated with calcium hydroxide the mixture showed pink colour when burette displayed the value of 35.5 mL whereas the burette showed 25.5 mL initially. The concentration of H₂SO₄ is_____M (Nearest integer)

An organic compound on combustion gives 0.22 g of CO₂ and 0.126 g of H₂O. If the percentage of C in given organic compound is 40%, the percentage of H will be?

A metal surface of 100 cm2 area has to be coated with nickel layer of thickness 0.001mm. A current of 2A was passed through a solution of Ni (NO₃)₂ for 'x' seconds to coat the desired layer. The value of x is_____ (Nearest integer)
 (P_Ni (density of Nickel) is 10 gmL^-1, Molar mass of Nickel is 60 gmol^-1 F = 96500 C mol^-1)

Solution of 12 g of non-electrolyte (A) prepared by dissolving it in 1000 mL of water exerts the same osmotic pressure as that of 0.05 M glucose solution at the same temperature. The empirical formula of A is CH₂O. The molecular mass of A is ____ g. (Nearest integer)

A₂+B₂→2AB. \(ΔH^0_f\)= -200 kJ mol^-1 AB, A2 and B2 are diatomic molecule. If the bond enthalpies of A₂, B₂ and AB are in the ratio 1:0.5:1, then the bond enthalpy of A₂ is ___ kJmol^-1 (Nearest integer)