List of top Chemistry Questions asked in JEE Main

Given, $E^\circ _{Cr ^{3+}/Cr} =-0.74\, V;E^\circ_{MnO^-_4/Mn^{2+}}=1.51\, V$ $\, \, \, \, \, E^\circ _{Cr_2 O ^{2-}_7/Cr^{3+}} =-1.33\, V;E^\circ_{Cl/Cl^-}=1.36\, V$ Based on the data given above strongest oxidising agent will be

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

For gaseous state, if most probable speed is denoted by $c *$, average speed by $\overline{C}$ and root square speed by $c$, then for a large number of molecules, the ratios of these speeds are

The standard enthalpies of formation of $CO_2(g), H_2O(l)$ and glucose(.v) at 25$^{\circ}$C- are 400 kJ/ mol. -300 kJ/mol and - 1300 kJ/mol, respectively. The standard enthalpy of combustion per gram of glucose at 25$^{\circ}$C is

\({(1) \,N_2(g) +3H_2(g)<=> 2NH_3(g), K_1}\)
\({(2) \,N_2(g) +O_2(g)<=> 2NHO(g), K_2}\) 
\({(3) \,H_2(g) +\frac{1}{2}O_2(g)<=> H_2O(g), K_3}\) 
The equation for the equilibrium constant of the reaction 
\({2NH_3(g) +\frac{5}{2}O_2(g)<=> 2NO(g), 3H_2O(g)}\), \((K_4)\) in terms of \(K_1\) and \(K_3\) is:

Calcination is the process in which:

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 :

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

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 $(A)$.

Formaldehyde can be distinguished from acetaldehyde by the use of :

The correct set of four quantum numbers for the valence electrons of rubidium atom $(Z = 37)$ is

The order of basicity of amines in gaseous state is:

Sodium Carbonate cannot be used in place of $(NH_4)_2CO_3$ for the identification of $Ca^{2+},\, Ba^{2+}$ and $Sr^{2+}$ ions (in group V) during mixture analysis because :

The molarity of a solution obtained by mixing $750\, mL$ of $0.5\, M \,HCl$ with $250\, mL$ of $2 \,M \,HCl$ will be

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 :