List of top Chemistry Questions asked in JEE Main

Which of the following oxoacids of sulphur contains \(S\) in two different oxidation states?

The correct IUPAC name of the following compound is:

Fig.

The major product (P) of the given reaction is (where, Me is –CH3)

Fig. 
Fig.

 

 

 



In the above reaction ‘A’ is

Isobutyraldehyde on reaction with formaldehyde and K2CO3 gives compound ‘A’. Compound ‘A’ reacts with KCN and yields compound ‘B’, which on hydrolysis gives a stable compound ‘C’. The compound ‘C’ is

With respect to the following reaction, consider the given statements:

Fig








(A) o-Nitroaniline and p-nitroaniline are the predominant products.
(B) p-Nitroaniline and m-nitroaniline are the predominant products.
(C) HNO3 acts as an acid.
(D) H2SO4 acts as an acid.
Choose the correct option.

Given below are two statements, one is Assertion (A) and other is Reason (R).

Assertion (A): Natural rubber is a linear polymer of isoprene called cis-polyisoprene with elastic properties.
Reason (R): The cis-polyisoprene molecules consist of various chains held together by strong polar interactions with coiled structure.

In the light of the above statements, choose the correct one from the options given below:

When sugar ‘X’ is boiled with dilute H2SO4 in alcoholic solution, two isomers ‘A’ and ‘B’ are formed. ‘A’ on oxidation with HNO3 yields saccharic acid whereas ‘B’ is laevorotatory. The compound ‘X’ is :
The drug tegamet is:
100 g of an ideal gas is kept in a cylinder of 416 L volume at 27°C under 1.5 bar pressure. The molar mass of the gas is ________ g mol–1. (Nearest integer). (Given : R = 0.083 L bar K–1 mol–1)
For combustion of one mole of magnesium in an open container at 300K and 1bar pressure, ΔCHΘ=–601.70kJ mol–1, the magnitude of change in internal energy for the reaction is______ kJ. (Nearest integer) (Given : R = 8.3 J K–1 mol–1)
2.5 g of protein containing only glycine (C2H5NO2) is dissolved in water to make 500 mL of solution. The osmotic pressure of this solution at 300 K is found to be 5.03 × 10–3 bar. The total number of glycine units present in the protein is _______.
(Given : R = 0.083 L bar K–1 mol–1)

For the given reactions
Sn2+ + 2e– → Sn
Sn4+ + 4e– → Sn
the electrode potentials are;
\(E^{∘}_{Sn^{2+}/Sn}=−0.140V \) and \(E^{∘}_{Sn^{4+}Sn} =−0.010 V.\)
The magnitude of standard electrode potential for \(Sn^{4+}/Sn^{2+}\) i.e.
\(E^{∘}_{Sn^{4+}/Sn^{2+}}\)
is _________ × 10–2 V. (Nearest integer)

A radioactive element has a half life of 200 days. The percentage of original activity remaining after 83 days is ________. (Nearest integer) (Given : antilog 0.125 = 1.333, antilog 0.693 = 4.93)
[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_______.
(a)CoCl3⋅4NH3,(b)CoCl3⋅5NH3,(c)CoCl3.6NH3 and (d)CoCl(NO3)2⋅5NH3.Number of complex(es) which will exist in cis-trans form is/are______.
The complete combustion of 0.492 g of an organic compound containing ‘C’, ‘H’ and ‘O’ gives 0.793 g of CO2 and 0.442 g of H2O. The percentage of oxygen composition in the organic compound is_____.[nearest integer]
Correct statement about photo-chemical smog is:
A commercially sold conc. HCl is 35% HCl by mass. If the density of this commercial acid is 1.46 g/mL, the molarity of this solution is :
(Atomic mass : Cl = 35.5 amu, H = 1 amu)
An evacuated glass vessel weighs 40.0 g when empty, 135.0 g when filled with a liquid of density 0.95 g mL–1 and 40.5 g when filled with an ideal gas at 0.82 atm at 250 K. The molar mass of the gas in g mol–1 is: (Given : R = 0.082 L atm K–1 mol–1)
If the radius of the 3rd Bohr’s orbit of hydrogen atom is r3 and the radius of 4th Bohr’s orbit is r4. Then
Consider the ions/molecules \(O^{2+}, O_2, O_2^-, O_2^{2-}\)For increasing bond order the correct option is
The \(\left(\frac{\partial E}{\partial T}\right)_p\) of different types of half cells are as follows:
ABCD
1 × 10-42 × 10-40.1 × 10-40.2 × 10-4

(Where E is the electromotive force)
Which of the above half cells would be preferred to be used as reference electrode?

Choose the correct stability order of group 13 elements in their +1 oxidation state
Given below are two statements:
Statement I : According to the Ellingham diagram, any metal oxide with higher ΔG° is more stable than the one with lower ΔG°.
Statement II :The metal involved in the formation of oxide placed lower in the Ellingham diagram can reduce the oxide of a metal placed higher in the diagram.
In the light of the above statements, choose the most appropriate answer from the options given below