List of top Chemistry Questions asked in JEE Main

At 35$^{\circ}$C, the vapour pressure of $CS_2$ is 512 mm Hg and that of acetone is 344 mm Hg. A solution of $CS_2$, in acetone has a total vapour pressure of 600 mm Hg. The false statement amongst the following is :

Two open beakers one containing a solvent and the other containing a mixture of that solvent with a non volatile solute are together sealed in a container. Over time:

The de Broglie wavelength of an electron in the $4^{th}$ Bohr orbit is :

Among (a) - (d), the complexes that can display geometrical isomerism are : $\left(a\right)\,\left[Pt\left(NH_{3}\right)_{3}Cl\right]^{+}$ $\left(b\right)\,\left[Pt\left(NH_{3}\right)Cl_{5}\right]^{-}$ $\left(c\right)\,\left[Pt\left(NH_{3}\right)_{2}Cl\left(NO\right)_{2}\right]$ $\left(d\right)\,\left[Pt\left(NH_{3}\right)_{4}ClBr\right]^{2+}$

Among the statements (A)-(D), the correct ones are : (a) Lithium has the highest hydration enthalpy among the alkali metals. (b) Lithium chloride is insoluble in pyridine. (c) Lithium cannot form ethynide upon its reaction with ethyne. (d) Both lithium and magnesium react slowly with $H_2O$ .

Hydrogen has three isotopes (A), (B) and (C). If the number of neutron(s) in (A), (B) and (C) respectively, are (x), (y) and (z), the sum of (x), (y) and (z) is :

The solubility product of $Cr(OH)_3$ at $298 \,K$ is $6.0 \times 10^{-31}.$ The concentration of hydroxide ions in a saturated solution of $Cr(OH)_3$ will be :

Among statements (a)-(d), the correct ones are: (a) Decomposition of hydrogen peroxide gives dioxygen. (b) Like hydrogen peroxide,compounds, such as $KClO_3, Pb (NO_3)_2$ and $NaNO_3$ when heated liberate dioxygen. (c) 2-Ethylanthraquinone is useful for the industrial preparation of hydrogen peroxide. (d) Hydrogen peroxide is used for the manufacture of sodium perborate.

In comparison to the zeolite process for the removal of permanent hardness, the synthetic resins method is :

Complex X of composition $Cr(H_2O)_6Cl_n$ has a spin only magnetic moment of 3.83 BM. It reacts with $AgNO_3$ and shows geometrical isomerism. The IUPAC nomenclature of X is :

The correct order of the spin-only magnetic moments of the following complexes is : $(I)\, [Cr(H_2O)_6]Br_2$ $(II)\, Na_4[Fe(CN)_6]$ $(III)\, Na_3[Fe(C_2O_4)_3] (\Delta_0 > P)$ $(IV)\, (Et_4N)_2[CoCl_4]$

The IUPAC name of the complex $[Pt(NH_3)_2Cl(NH_2CH_3)]Cl$ is :

The complex that can show fac- and mer- isomers is :

The time period of revolution of electron inits ground state orbit in a hydrogen atom is $1 .6 \times 10^{- 16}$ s. The frequency of revolution of the electron in its first excited state (in $s ^{- 1}$) is :

The process that is $NOT$ endothermic in nature is :-

A crystal is made up of metal ions 'M $_{1}$ ' and 'M $_{2}$ ' and oxide ions. Oxide ions. form a ccp lattice structure. The cation '$M_1$ occupies $50 \%$ of octahedral voids and the cation 'M $_{2}$ ' occupies $12.5 \%$ of tetrahedral voids of oxide lattice. The oxidation numbers of ' $M _{1}$ ' and ' $M _{2}$ ' are, respectively:

An element crystallises in a face-centred cubic (fcc) unit cell with cell edge a. The distance between the centres of two nearest octahedral voids in the crystal lattice is

Cast iron is used for the manufacture of :

A sample of red ink (a colloidal suspension) is prepared by mixing eosin dye, egg white, $HCHO $ and water. The component which ensures stability of the ink sample is :-

According to the following diagram, A reduces $BO_2$ when the temperature is :

For following reactions ${A ->[700\,K][] Product}$ ${A ->[500\,K][{\text{catalyst}}] Product}$ it was found that the $E_a$ is decreased by 30 k J/mol in the presence of catalyst. If the rate remains unchanged, the activation energy for catalysed reaction is (Assume pre exponential factor is same):

The major product formed in the following reaction is : $CH _{3} CH = CHCH \left( CH _{3}\right)_{2} \stackrel{ HBr }{\longrightarrow}$

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 $\left.\left( N _{ A }\right)=6 \times 10^{23} \,mol ^{-1}\right)$