List of top Chemistry Questions asked in JEE Main

Stability of the species $ Li_2 , Li_2^- , \, \, and \, \, Li_2^+ $ increases in the order of

For which of the following compounds Kjeldahl method can be used to determine the percentage of Nitrogen ?

Experimentally it was found that a metal oxide has formula $ M_{0.98}O. $ Metal $M$, present as $ M^{2+} $ and $ M^{3+} $ in its oxide.Fraction of the metal which exists as $ M^{3+} $ would be

How many grams of methyl alcohol should be added to $10$ litre tank of water to prevent its freezing at $268\, K$ ? $\left(K_{f} \, for\, water\, is \,1.86 K\, kg \, mol^{-1} \right)$

$XeO_4$ molecule is tetrahedral having :

$6$ litres of an alkene require $27$ litres of oxygen at constant temperature and pressure for complete combustion. The alkene is:

Consider the following reaction, $xMnO_4^- + yC_2O_4^{2-}+zH^+ \rightarrow xMn^{2+}+2yCO_2 + \frac{z}{2}H_2O$ The values of x, y and z in the reaction are, respectively

Potassium dichromate when heated with concentrated sulphuric acid and a soluble chloride, gives brown-red vapours of :

The coagulating power of electrolytes having ions $Na^+, Al^{3+}$ and $Ba^{2+}$ for arsenic sulphide sol increases in the order

Number of atoms in the following samples of substances is largest in :

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?

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

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

The 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:

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 of the following molecules is expected to exhibit diamagnetic behaviour?

Which one has the highest boiling point?

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