List of top Questions asked in JEE Main- 2013

Vapour pressure of pure benzene is $119$ torr and that of toluene is $37.0$ torr at the same temperature. Mole fraction of toluene in vapour phase which is in equilibrium with a solution of benzene and toluene having a mole fraction of toluene $0.50$, will be :

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

Glycosidic linkage is actually an :

Formaldehyde can be distinguished from acetaldehyde by the use of :

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

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

Which one has the highest boiling point?

Which one of the following is most stable?

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

Compound $( A ), C_8H_9Br$ gives a white precipitate when warmed with alcoholic $AgNO_3$. Oxidation of $(A)$ gives an acid $(B)$, $C_8H_6O$ 4. $(B)$ easily forms anhydride on heating. Identify the compound $(A)$.

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 ?

Oxidation state of sulphur in anions $SO^{2-}_{3}. S_{2}O^{2-}_{4}$ and $S_{2}O^{2-}_{6}$ increases in the orders:

\(12\, g\) of a nonvolatile solute dissolved in \(108\, g\) of water produces the relative lowering of vapor pressure of \(0.1.\)The molecular mass of the solute is :

Bond distance in $HF$ is $9.17 \times 10^{-11}\, m$. Dipole moment of $HF$ is $6.10^4 \times 10^{-30}\, Cm$ . The percentage ionic character in $HF$ will be : (electron charge $= 1.60 \times 10^{-19}\, C$)

The Wurtz-Fittig reaction involves condensation of:

$XeO_4$ molecule is tetrahedral having :

A solution of copper sulphate $\left(CuSO_{4}\right)$ is electrolysed for 10 minutes with a current of $1.5$ amperes. The mass of copper deposited at the cathode (at. mass of $Cu = 63u$) is :

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

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

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?

Electrode potentials (E$^{\circ}$) are given below : $Cu^{+}/Cu=+0.52\, V,$ $Fe^{3+}/Fe^{2+} = +0.77 \,V,$ $\frac{1}{2}I_{2}\left(s\right)/I^{-} = 40.54 \,V,$ $Ag^{+}/Ag =+ 0.88\,V.$ Based on the above potentials, strongest oxidizing agent will be :

Which one of the following is the wrong assumption of kinetic theory of gases?

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

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