List of top Chemistry Questions

In vapour state sulphur is paramagnetic in nature. In vapour state sulphur exists as $S_2$ molecule.

In the metallury of aluminium, purified $Al_2O_3$ is mixed with $Na_3AlF_6$ or $CaF_2$. $Na_3AlF_6$ or $CaF_2$ lowers the melting point of mixture and increases its conductivity.

In the presence of alkaline $KMnO_{4} 4-$ methylacetophenone is oxidised to benzoic acid. Keto group is oxidised to $??OOH$ group.

In the reaction, $2Cu_{2}O_{\left(s\right)}+Cu_{2}S_{\left(s\right)} \rightarrow 6 Cu_{\left(s\right)}+SO_{2\left(g\right)}$ copper acts as a reductant and sulphur acts as an oxidant. The given reaction is not a redox reaction.

In Rutherford?? $\alpha$ -particle scattering experiment, most of the $\alpha$ -particles were deflected by nearly $180^{\circ}$. The positive charge of the atom is spread throughout the atom that repelled and deflected the positively charged $\alpha$-particles.

In $NH_3, N$ is $sp^3$ hybridised but bond angle is $107^{\circ}$. Shape of $NH_{3}$ molecule is trigonal pyramidal.

In hydrogen and hydrogen like species, orbital energy depends only on the quantum number $n$ whereas in multi-electron atoms it depends on quantum numbers $n$ and $I$. The principal quantum number determines the size and the energy of the orbital.

In crystalline solids, the value of resistance is different in different directions. Crystalline solids are isotropic in nature.

Hydrolysis of ester is an example of auto catalytic reaction. A catalyst speeds up the process without participating in the mechanism.

Hofmann degradation of benzamide gives aniline. Hofmann bromamide degradation reaction can be used for descending amine series.

$HNO_{2}$ can act both as a reducing agent and an oxidising agent. In $HNO_{2},$ oxidation state of nitrogen is $+3 $ which can change from $-3$ to $+5$.

Haloalkanes react with $KCN$ to form alkyl cyanides as main product while with $AgCN$ form isocyanide as the main product. $KCN$ and $AgCN$, both are ionic compounds.

Glucose gets oxidised to gluconic acid on reaction with mild oxidising agent like bromine water. Glucose contains a keto group.

Glass panes fixed to windows or doors of old buildings are slightly thicker at the bottom than at the top. Glass is a pseudo solid or supercooled liquid.

Geometrical isomerism is also called cis-trans isomerism. Tetrahedral complexes show geometrical isomerism.

Fullerenes are the only pure form of carbon. It contains twenty, five-membered rings and twelve, six-membered rings.

For the element $O$ or $F$, the electron gain enthalpy is less negative than that of the succeeding element. Electron gain enthalpy becomes less negative as we go down a group.

$[Fe(H_{2}O ) _{6}]^{3+}$ is strongly paramagnetic whereas $[Fe(CN)_{6}]^{3-}$ is weakly paramagnetic. $H_{2}O$ is a weak field ligand and $CN^{-}$ is a strong field ligand.

Diamond is the hardest substance on the earth. It has high melting point.

Decomposition of hydrogen peroxide is an example of disproportionation reaction. In a disproportionation reaction, an element in one oxidation state is simultaneously oxidised and reduced.

Cresols are less acidic than phenol. Electron releasing groups do not favour the formation of phenoxide ion.

$CsCl$ has body-centred cubic arrangement. $CsCl$ has one $Cs^+$ ion and $8\, Cl^-$ ions in its unit cell.

$Cr^{2+}$ is reducing and $Mn^{3+}$ is oxidising. $Cr^{2+}$ and $Mn^{3+}$ have $d^4$ configuration.

Copper dissolves in dilute nitric acid but not in dilute $HCl$. Copper has positive $E^?$.

Common name of $1,1$-dichloroethane is ethylidene chloride. Ethylidene chloride is a gem-dihalide.