List of top Chemistry Questions

Lithium metal crystallizes in a body centred cubic crystal. If the length of the side of the unit cell of lithium is $351\, pm,$ the atomic radius of the lithium will be

Oxidation number of $S$ in $ H_{2}S_{2}O_{8}$ is

For the redox reaction, $Zn + NO _{3}^{-} \longrightarrow Zn ^{2+}+ NH _{4}^{+}$ in basic medium, coefficients of $Zn , NO _{3}^{-}$, and $OH ^{-}$in the balanced equation respectively, are

How many bonds does $B_{2}$ have?

How many coulombs of electricity are required for reduction of $1$ mole of $ MnO_{4}^{-} $ to $ Mn^{2+}$ ?

Which of the following metal sols cannot be prepared by Bredig's arc metliod?

Which of the following is not correct regarding the elecolytic preparation of $H_{2}O_{2}$ ?

Which of the following reactions involves carbon-carbon bond formation

Which of the following coordination entities should be expected to absorb light of lowest frequency?

On the basis of the following thermochemical data $: \left(\Delta f G^{o}H^{+}_{\left(aq\right)}=0\right)$ $H_{2}O\left(\ell\right) \rightarrow H^{+}\left(aq\right)+OH^{-}\left(aq\right); \Delta H=57.32kj$ $H_{2}\left(g\right)+\frac{1}{2}O_{2}\left(g\right) \rightarrow H_{2}O\left(\ell\right); \Delta H=-286.20kj$ The value of enthalpy of formation of $OH^-$ ion at $25^o\,C$ is :

Copper crystallizes in fcc with a unit cell length of 361 pm. What is the radius of copper atom ?

Which of the following has an optical isomer ?

Given $: E^{o}_{Fe^{3+}/Fe}=-0.036V, E^{o}_{Fe^{2+}/Fe}=-0.439V$. The value of standard electrode potential for the change, $Fe^{3+}_{\left(aq\right)}+e^{-} \rightarrow Fe^{2+}\left(aq\right)$ will be :

In a fuel cell methanol is used as fuel and oxygen gas is used as an oxidizer. The reaction is$CH_{3}OH\left(\ell\right)+\frac{3}{2}O_{2}\left(g\right) \rightarrow CO_{2}\left(g\right)+2H_{2}O\left(\ell\right)$ At $298K$ standard Gibb?s energies of formation for $CH_{3}OH\left(\ell\right), H_{2}O\left(\ell\right)$ and $CO_{2}\left(g\right)$ are $-166.2, -237.2$ and $-394.4\, kJ\, mol^{-1}$ respectively. If standard enthalpy of combustion of methanol is $-726kJ \,mol^{-1}$ , efficiency of the fuel cell will be

In an atom, an electron is moving with a speed of $600\,m/s$ with an accuracy of $0.005\%.$ Certainity with which the position of the electron can be located is ($h = 6.6 ? 10^{-34} kg\, m^2\,s^{-1}$ , mass of electron, $e_m = 9.1?10^{- kg}$ )

A liquid was mixed with ethanol and a drop of concentrated $H_2SO_4$ was added. A compound with a fruity smell was formed. The liquid was :

Which polymers occur naturally ?

For which of the following pairs, magnetic moment is same?

Which of the following azeotropic solutions has the boiling point less than boiling point of the constituents $A$ and $B$?

Select the incorrect statement, among the following.

The correct set of reagents for the following conversion is

A sample of $0.42 \,mg \,{ }^{233} UF _{6}$ shows an activity of $9.88 \times 10^{4}$ count per second. Its $t_{1 / 2}$ is

Sodium crystallizes in bcc arrangement with the interfacial separation between the atoms at the edge $53\, pm$. The density of the solid is

Which of the following coordination entities should be expected to absorb light of lowest frequency?

The increasing order of hydrolysis of the following compounds is