List of top Chemistry Questions asked in JEE Main

The radius of the largest sphere which fits properly at the centre of the edge of body centred cubic unit cell is : (Edge length is represented by 'a') :

Chlorine on reaction with hot and concentrated sodium hydroxide gives :

For the reaction, ${2A + B \to }$ products, when the concentrations of A and B both where doubled , the rate of the reaction increased from $0.3 \; mol \; L^{-1} s^{-1 }$ to $2.4 \; mol \; L^{-1} s^{-1}$. When the concentration of A alone is doubled, the rate increased from $0.3 \; mol \; L^{-1} s^{-1}$ to $0.6 \; mol \; L^{-1} s^{-1}$ Which one of the following statements is correct ?

Ozone is destroyed by CFCs in the upper stratosphere Ozone holes increase the amount of UV radiation reaching the earth.

Aluminium is usually found in $+3$ oxidation stagte. In contarast, thallium exists in $+1$ and $+3$ oxidation states. This is due to :

Which of the following is a thermosetting polymer?

The $pH$ of rain water, is approximately :

An example of solid sol is :

Molecules of benzoic acid (C$_{6}H_{5}$COOH) dimerise in benzene. $'w' \,g$ of the acid dissolved in $30\, g$ of benzene shows a depression in freezing point equal to $2K$. If the percentage association of the acid to form dimer in the solution is $80$, then $w$ is : (Given that $K_{f} = 5 K\, kg\, mol^{-1} $, Molar mass of benzoic acid $= 122 \,g\, mol^{-1})$

The strength of $11.2$ volume solution of $H_2O_2$ is : [Given that molar mass of $H = 1\, g$ $mol^{-1}$ and $O = 16\, g\, mol^{-1}]$

The vapour pressures of pure liquids $A$ and $B$ are $400$ and $600\, mmHg$, respectively at $298\,K$. On mixing the two liquids, the sum of their initial volumes is equal to the volume of the final mixture. The mole fraction of liquid $B$ is $0.5$ in the mixture. The vapour pressure of the final solution, the mole fraction of components $A$ and $B$ in vapour phase, respectively are -

The anodic half-cell of lead-acid battery is recharged unsing electricity of $0.05$ Faraday. The amount of $ {PbSO_4}$ electrolyzed in g during the process in : (Molar mass of $ {PbSO_4 = 303 \; g \; mol^{-1}}$)

In the cell ${Pt(s) | H_2(g , 1 bar | HCl(aq) | Ag(s) | Pt(s)} $ the cell potential is 0.92 when a $10^{-6}$ molal HCl solution is used. THe standard electrode potential of ${(AgCl/Ag,Cl^{-})}$ electrode is : $\left\{ \text{given} , \frac{2.303RT}{F} = 0.06 V \; at \; 298K\right\}$

${5.1g \; NH_4SH }$ is introduced in $3.0\, L$ evacuated flask at ${327^{\circ}C}$. 30% of the solid ${NH4SH}$ decomposed to ${NH_3}$ and ${H2S}$ as gases. The Kp of the reaction at ${327^{\circ}C}$ is ${(R = 0.082 \; L \; atm \; mol^{-1} K^{-1}}}$, Molar mass of ${S = 32 \; g \; mol/^{01}}$, molar mass of ${N = 14g \, mol^{-1}}$)

Homoleptic octahedral complexes of a metal ion '${M^{3+} }$' with three monodentate ligands and $L_1, L_2, L_3$ absorb wavelengths in the region of green, blue and red respectively. The increasing order of the ligand strength is :

The peptide that gives positive ceric ammonium nitrate and carbylamine tests is :

The Mond process is used for the

The structures of beryllium chloride in the solid state and vapour, phase, respectively,are :

The aerosol is a kind of colloid in which :

The concentration of dissolved oxygen $(DO)$ in cold water can go upto :

The ratio of number of atoms present in a simple cubic, body centered cubic and face centered cubic structure are, respectively :

The process with negative entropy change is :

The correct statements among (a) to (b) are: (a) saline hydrides produce $H_2$ gas when reacted with ${H2O}$. (b) reaction of $LiAH_4$ with $BF_3$ leads to $B_2H_6$. (c) $PH_3$ and $CH_4$ are electron - rich and electronprecise hydrides, respectively. (d) HF and $CH_4$ are called as molecular hydrides.

The primary pollutant that leads to photochemical smog is :

The IUPAC symbol for the element with atomic number $119$ would be :