List of top Chemistry Questions asked in JEE Main

In nucleophilic substitution reaction, order of halogens as incoming (attacking) nucleophile is: $I^- > \, Br^{-} > \, Cl^-$ The order of halogens as departing nucleophile should be:

The rate of a reaction doubles when its temperature changes from $300\, K$ to $310\,K$. Activation energy of such a reaction will be $(R = 8.314 JK^{-1} \,mol^{-1}$ and $log \,2 = 0.301)$

Which one of the following statements about packing in solids is ?

Rate of dehydration of alcohols follows the order:

Which of the free radical is most stable?

$10\, mL$ of $2(M)$ $NaOH$ solution is added to $200\, mL$ of $0.5 (M)$ of $NaOH$ solution. What is the final concentration ?

The reaction of phenol with benzoyl chloride to give phenyl benzoate is known as :

The order of reactivity of the given haloalkanes towards nucleophile is :

Which of the following represents the correct order of increasing first ionisation enthalpy for $Ca, Ba, S, Se$ and $Ar$?

Solid $Ba(NO_3)_2$ is gradually dissolved in a $1.0 \times 10^{-4}$ M $Na_2CO_3$ solution. At which concentration of $Ba^{2+}$, precipitate of $BaCO_3$ begins to form ? ($K_{sp}$ for $BaCO_3 = 5.1 \times 10^{-9}$)

The correct order of viscosity of the following liquids will be:

Which one of the following molecules is expected to exhibit diamagnetic behaviour?

Four successive members of the first row transition elements listed below with atomic numbers. Which one of them is expected to have the highest $E_{m{^{3+}}/m{^{2+}}}^{\circ}$value?

Which one has the highest boiling point?

The order of increasing sizes of atomic radii among the elements $O, S, Se$ and $As$ is :

The catenation tendency of $C, Si$ and $Ge$ is in the order Ge $

Which of the following arrangements does not represent the correct order of the property stated against it?

Which of the following is diamagnetic?

The density of $3M$ solution of sodium chloride is $1.252\, g\, mL^{-1}$. The molality of the solution will be: (molar mass, $NaCl = 585\, g\, mol^{-1}$)

In Goldschmidt aluminothermic process which of the following reducing agents is used:

The rate constant of a zero order reaction is $2.0 \times 10^{-2}\, mol \,L^{-1}\, s^{-1}$. If the concentration of the reactant after $25$ seconds is $0.5\,M$. What is the initial concentration ?

In which of the following pairs of molecules/ions both the species are not likely to exist?

Copper crystallises in fcc with a unit length of $361\,pm$. What is the radius of copper atom ?

In a face centred cubic lattice, atoms of $A$ form the comer points and atoms of $B$ form the face centred points. If two atoms of $A$ are missing from the comer points, the formula of the ionic compound is :

The first ionisation potential of $Na$ is $5.1\, eV$. The value of electron gain enthalpy of $Na^+$ will be