List of top Chemistry Questions asked in JEE Main

IUPAC name of the compound C7H12O2?

Match the terms in Column-I with their description in Column-II:

 Column-I Column-II (P) N2O5 (i) N–N bond (Q) N2O (ii) N–O–N bond (R) N2O4 (iii) N=N / NN bond (S) NO2 (iv) N=O bond 

Oxidation number of Mo in Ammonophosphomolybdate

Number of ambidentate ligands in given complex [M(en)(SCN)4] : 

Which of the following slows down the process of setting of the cement ? 

The value of log10K for a reaction A ⇋ B is (Given ΔHº298K = –54.67 kJmol–1 ΔSº298K = 10 kJmol–1 and R = 8.314 JK–1mol–1 2.303 × 8.314 × 298 = 5705) 

If the radius of ground state hydrogen is 51 pm, find out the radius of 5th orbit of Li2+ ions. (closest integer)

What is the ratio of σ and pi bonds in pyrophosphoric acid?

In a container at a constant temperature , arrange the RMS velocity of the following: Ne, Cl2 , UF6

Match the Column:
 Column I Column II
(A).ClO2-(1).Linear
(B).N3-(2).Tetrahedral
(C).NH4+(3).Bent
(D).SF4(4).See-Saw
In base vs Acid titration, at the end pointmethyl orange is present as

C(s)+O2(g)→CO2(g)+400 kJ
C(s)+\(\frac{1}{2}\) O2(g)→CO(s)+100 kJ
When coal of purity 60% is allowed to burn in presence of insufficient oxygen, 60% of carbon is converted into ‘CO’ and the remaining is converted into ‘CO2’. The heat generated when 0.6 kg of coal is burnt 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.)
In the given reaction,
\( \begin{array}{l}X+Y+3Z\rightleftharpoons XYZ_3\end{array}\)
if one mole of each of X and Y with 0.05 mol of Z gives compound XYZ3. (Given : Atomic masses of X, Y and Z are 10, 20 and 30 amu, respectively.) the yield of XYZ3 is _______ g. (Nearest integer)
The longest wavelength of light that can be used for the ionisation of lithium atom (Li) in its ground state is \(x × 10^{–8}\ m\). The value of \(x\) is ______. (Nearest Integer)
(Given : Energy of the electron in the first shell of the hydrogen atom is \(2.2 \times 10^{–18} J\);
\(h = 6.63 × 10^{–34}Js\) and \(c = 3 × 10^8 ms^{–1}\))

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)
4.0 L of an ideal gas is allowed to expand isothermally into vacuum until the total volume is 20 L. The amount of heat absorbed in this expansion is ____ L atm.
[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)

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:

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]