List of top Chemistry Questions

Among the following molecules / ions, $C^{2-}_{2}, N^{2-}_{2}, O^{2-}_{2}, O_{2}$ which one is diamagnetic and has the shortest bond length?

The major product formed in the following reaction is:

Correct statements among $a$ to $d$ regarding silicones are : (a) They are polymers with hydrophobic character (b) They are biocompatible. (c) In general, they have high thermal stability and low dielectric strenth. (d) Usually, they are resistant to oxidation and used as greases.

The amphoteric hydroxide is :

The percentage composition of carbon by mole in methane is :

If the kinetic energy of $O_2$ gas is $4.0 \,kJ \; mol^{-1}$ . its RMS speed in $cm \; s^{-1}$ is

The structure of Nylon-6 is :

Polyblend, a fine powder of recycled modified plastic, has proved to be a good material for:

The alkane that gives only one mono-chloro product on chlorination with $Cl_2$ in presence of diffused sunlight is :

Consider the $bcc$ unit cells of the solids $1$ and $2$ with the position of atoms as shown below. The radius of atom $B$ is twice that of atom $A$. The unit cell edge length is $50\%$ more in solid $2$ than in $1$. What is the approximate packing efficiency in solid $2$ ?

${K_2HgI_4}$ is $40\%$ ionised in aqueous solution. The value of its van't Hoff factor (i) is :

If dichloromethane (DCM) and water ${(H_2O)}$ are used for differential extraction, which one of the following statements is correct ?

With respect to an ore, Ellingham diagram helps to predict the feasibility of its -

For a reaction, activation energy E$_a$=0 and the rate constant at 200K is 1.6×10$^6$s$^{-1}$. The rate constant at 400K will be- [Given that gas constant] R= 8.314 J K$^{-1}$ mol$^{-1}$

The pair that has similar atomic radii is :

Under isothermal condition, a gas at 300 K expands from 0.1 L to 0.25 L against a constant externalpressureof2bar Theworkdonebythe gas i s : [Given that 1Lbar= 100J)

If the rate constant for a first order reaction is k, the time(t) required for the completion of 99% of the reaction is given by :

In which case change in entropy is negative ?

Sodium metal on dissolution in liquid ammonia gives a deep blue solution due to the formation of:

For the following reactions, equilibrium constants are given : $S\left(s\right)+O_{2}\left(g\right) $${\rightleftharpoons}$$SO_{2}\left(g\right); K_{1} =10^{52}$ $2S\left(s\right)+3O_{2}\left(g\right) $${\rightleftharpoons}$$2SO_{3}\left(g\right); K_{2} = 10^{129}$ The eqilibrium constant for the reaction, $2SO_{2}\left(g\right)+O_{2}\left(g\right)$${\rightleftharpoons}$$2SO_{3}\left(g\right)$ is :

$ {Mn_2(CO)_{10}}$ is an organometallic compound due to the presence of :

During nitration of benzene, the attacking electrophile is

Saccharin an artificial sweetener is manufactured from

What is hybridization of O in H₂O?

Which cannot behave as a nucleophile for S_N2 reaction?