List of top Chemistry Questions asked in JEE Main

Kraft temperature is the temperature

Two monomers in maltose are :

A diatomic molecule $X_{2}$ has a body-centred cubic (bcc) structure with a cell edge of $300\, pm$. The density of the molecule is $6.17 \,g \,cm ^{-3}$. The number of molecules present in $200\, g$ of $X _{2}$ is (Avogadro constant $\left.\left( N _{ A }\right)=6 \times 10^{23} \,mol ^{-1}\right)$

The number of $sp^2$ hybrid orbitals in a molecule of benzene is :

'X' melts at low temperature and is a bad conductor of electricity in both liquid and solid state. X i s :

The number of bonds between sulphur and oxygen atoms in $S_2O^{2-}_8$ and the number of bonds between sulphur and sulphur atoms in rhombic sulphur, respectively, are:

The number of 2 -centre- 2 -electron and 3-centre-2-electron bonds in $B _{2} H _{6}$, respectively, are :

Fructose and glucose can be distinguished by :

A $10\, mg$ effervescent tablet contianing sodium bicarbonate and oxalic acid releases $0.25\, ml$ of ${CO_2}$ at $T$ = $298.15\, K$ and $p = 1$ bar. If molar volume of ${CO_2}$ is $25.0\, L$ under such condition, what is the percentage of sodium bicarbonate in each tablet ? [Molar mass of ${NaHCO_3 = 84 \; g \; mol^{-1}}$]

An element has a face-centred cubic (fcc ) structure with a cell edge of a. The distance between the centres of two nearest tetrahedral voids in the lattice is :

The correct decreasing order for acid strength is :

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

When the first electron gain enthalpy $( \Delta_{eg}H) $ of oxygen is $-141\, kJ/mol$, its second electron gain enthalpy is :

The volume strength of $1 \,M H _{2} O _{2}$ is (Molar mass of $\left. H _{2} O _{2}=34 \,g\, mol ^{-1}\right)$

1 g of non-volatile non-electrolyte solute is dissolved in 100g of two different solvents A and B whose ebullioscopic constants are in the ratio of 1 : 5. The ratio of the elevation in their boiling points, $\frac{\Delta T_b(A)}{\Delta T_b (B)}$, is:

A solution is prepared by dissolving $0.6\, g$ of urea (molar mass = $60\, g\, mol^{-1})$ and $1.8\, g$ of glucose (molar mass = $180\, g$ mol${-1}$) in $100\, mL$ of water at $27^{\circ}C$. The osmotic pressure of the solution is : $(R = 0.08206 \; L \; atm \; K^{-1} \; mol^{-1} ) $

Freezing point of a $4\%$ aqueous solution of $X$ is equal to freezing point of $12\%$ aqueous solution of $Y$. If molecular weight of $X$ is $A$, then molecular weight of $Y$ is :

In the following skew conformation of ethane, $H'-C-C-H''$ dihedral angle is :

Which of the following compounds is not aromatic ?

An aromatic compound $'A'$ having molecular formula ${C7H6O2}$ on treating with aqueous ammonia and heating forms compound $'B'$. The compound $'B'$ on reaction with molecular bromine and potassium hydroxide provides compound $'C'$ having molecular formula ${C_6H_7N}$. The structure of $'A'$ is :

Arrange the following amines in the decreasing order of basicity:

Ethylamine ${(C2H5NH2)}$ can be obtained from N-ethylphthalimide on treatment with :

Hinsberg's reagent is :

Among the following species, the diamagnetic molecule is

The product formed in the reaction of cumene with $O_2$ followed by treatment with dil. $HCl$ are :