List of top Chemistry Questions asked in JEE Main

Deuterium resembles hydrogen in properties but :
What is the correct order of the following elements with respect to their density ?
The parameters of the unit cell of a substance are a = 2.5, b = 3.0, c = 4.0, $\alpha=90^\circ, \beta=120^\circ, \gamma=90^\circ$. The crystal system of the substance is :
The number of stereoisomers possible for 1,2-dimethyl cyclopropane is :
An empty LPG cylinder weighs 14.8 kg. When full, it weighs 29.0 kg and shows a pressure of 3.47 atm. In the course of use at ambient temperature, the mass of the cylinder is reduced to 23.0 kg. The final pressure inside of the cylinder is _________ atm. (Nearest integer)

(Assume LPG of be an ideal gas)
The number of atoms in 8g of sodium is x \(\times\) 10\(^{23}\). The value of x is ____________. (Nearest integer)

[Given : \(N_A = 6.02 \times 10^{23}\ \mathrm{mol^{-1}}\)

Atomic mass of Na = 23.0 u]
If 80 g of copper sulphate \(\mathrm{CuSO_4 \cdot 5H_2O}\) is dissolved in deionised water to make 5L of solution. The concentration of the copper sulphate solution is x \(\times\) 10\(^{-3}\) mol L\(^{-1}\). The value of x is _____________.

[Atomic masses Cu : 63.54u, S : 32u, O : 16u, H : 1u]
A 50 watt bulb emits monochromatic red light of wavelength of 795 nm. The number of photons emitted per second by the bulb is x \(\times\) 10\(^{20}\). The value of x is __________. [Given : h = 6.63 \(\times\) 10\(^{-34}\) Js and c = 3.0 \(\times\) 10\(^8\) ms\(^{-1}\)]
If the conductivity of mercury at \(0^\circ\mathrm{C}\) is \(1.07 \times 10^{6}\ \mathrm{S\,m^{-1}}\) and the resistance of a cell containing mercury is \(0.243\ \Omega\), then the cell constant of the cell is \(x \times 10^{4}\ \mathrm{m^{-1}}\). The value of x is ____________. (Nearest integer)
The spin-only magnetic moment value of \(\mathrm{B_2^+}\) species is _____________ \(\times 10^{-2}\) BM. (Nearest integer)
[Given : \(\sqrt{3} = 1.73\)]
The sum of oxidation states of two silver ions in \(\mathrm{[Ag(NH_3)_2][Ag(CN)_2]}\) complex is _____________.
The oxide without nitrogen-nitrogen bond is :
Monomer units of Dacron polymer are :
Match List - I with List - II :

List - I (Colloid Preparation Method)List - II (Chemical Reaction)
(a)Hydrolysis(i)\(\mathrm{2AuCl_3 + 3HCHO + 3H_2O \to 2Au(sol) + 3HCOOH + 6HCl}\)
(b)Reduction(ii)\(\mathrm{As_2O_3 + 3H_2S \to As_2S_3(sol) + 3H_2O}\)
(c)Oxidation(iii)\(\mathrm{SO_2 + 2H_2S \to 3S(sol) + 2H_2O}\)
(d)Double Decomposition(iv)\(\mathrm{FeCl_3 + 3H_2O \to Fe(OH)_3(sol) + 3HCl}\)

Choose the most appropriate answer from the options given below.
Hydrogen peroxide reacts with iodine in basic medium to give :
Calamine and Malachite, respectively, are the ores of :
Number of paramagnetic oxides among the following given oxides is ____________.

\(\mathrm{Li_2O}\), \(\mathrm{CaO}\), \(\mathrm{Na_2O_2}\), \(\mathrm{KO_2}\), \(\mathrm{MgO}\) and \(\mathrm{K_2O}\)
The potassium ferrocyanide solution gives a Prussian blue colour, when added to :
The stereoisomers that are formed by electrophilic addition of bromine to trans-but-2-ene is/are :
Which one of the following gives the most stable Diazonium salt?
In the following sequence of reactions, \(\mathrm{C_3H_6 \xrightarrow{H^+/H_2O} A \xrightarrow[\text{dil KOH}]{KIO} B + C}\)
The compounds B and C respectively are :-
Given below are two statements :

Statement I : The nucleophilic addition of sodium hydrogen sulphite to an aldehyde or a ketone involves proton transfer to form a stable ion.

Statement II : The nucleophilic addition of hydrogen cyanide to an aldehyde or a ketone yields amine as final product.

In the light of the above statements, choose the most appropriate answer from the options given below :
Which one of the following compounds is aromatic in nature?
Identify A in the following reaction.
In the following sequence of reactions a compound A, (molecular formula \(\mathrm{C_6H_{12}O_2}\)) with a straight chain structure gives a \(\mathrm{C_4}\) carboxylic acid. A is :
\(\mathrm{A}\ \xrightarrow[\mathrm{H_3O^+}]{\mathrm{LiAlH_4}}\ \mathrm{B}\ \xrightarrow{\text{Oxidation}}\ \mathrm{C_4}\text{-carboxylic acid}\)