List of top Chemistry Questions

Oxidation state of oxygen in \(\text{H}_2\text{O}_2\)

Which of the following lanthanoid ion is cloured?

Match the following

Arrange the isoelectronic species in increasing order of ionic radius:
\(\text{Al}^{3+}\), \(\text{Na}^{+}\), \(\text{F}^{-}\), \(\text{O}^{2-}\)

Which among the following is most basic in aqueous medium

If the reaction is \( 3^{\text{rd}} \) order, if the concentration of reactant is doubled, then the rate is

3 g of benzoic acid is added to 25 g of benzene. \( \Delta T_f = 2.5\,\text{K} \) and \( K_f \) of benzene is 5. What is the experimental molecular mass of benzoic acid?

A 250 watt bulb emits monochromatic light wavelength 198.78 nm. How many photons are emitted by the bulb per second?

In the reaction, \( \text{O}_{2(g)} + 4\text{H}^+_{(aq)} + 4\text{e}^- \rightarrow 2\text{H}_2\text{O}_{(l)} \), the quantity of electricity required to reduce one mole of gaseous oxygen is ( \( E^\circ = 1.23\,\text{V} \) )

The technique is used to purify liquid having very high b.p and decompose at or below this boiling point is

\( \Delta G \) for \( 3\text{X}_{(g)} + 2\text{Y}_{(g)} \rightarrow 3\text{Z}_{(g)} \) at 293 K is
( \( \Delta H^\circ = -13\,\text{kJ mol}^{-1} \), \( \Delta S^\circ = -45\,\text{J mol}^{-1}\text{K}^{-1} \) )

The major products formed by heating \( \text{C}_6\text{H}_5\text{CH}_2 - \text{O} - \text{C}_6\text{H}_5 \) with HI are

Total number of electrons present around the central atom in order of \( \text{PCl}_5 \), \( \text{SF}_6 \), \( \text{SCl}_2 \)

The rate constant of a reaction at 400 K and 500 K are \( 0.04\,\text{min}^{-1} \) and \( 0.08\,\text{min}^{-1} \) respectively. The \( E_a \) of the reaction is about ( \( 2.303R = 19.15\,\text{J mol}^{-1}\text{K}^{-1} \) )

\( \text{CO}_2 \) is taken in a closed container initially at a pressure of 0.6 atm at 1500 K. After the addition of solid C, some of \( \text{CO}_2 \) is converted to CO. The equilibrium pressure is then 0.9 atm. Calculate the value of \( K_p \) at 1500 K.

product of aldol condensation is 1,3-diphenyl pro-3-ene-1-one, then its reactants are

Which metal added in fuel cell to make it more efficient?

Find the order of magnitude of electrode potential ($E^\circ_{\text{M}^{2+}/\text{M}}$) of
Cr, V, Mn, Fe, Co

Velocity of \( \text{I}^{\text{st}} \) orbit of hydrogen according to Bohr theory is \( v \), then what is the velocity of \( 3^{\text{rd}} \) orbit of hydrogen?

An organic compound (X) on reductive ozonolysis gave 1 mole of propanal-pent-3-one. Name the organic compound X.

What are possible structural isomers of \( \text{C}_3\text{H}_6\text{Cl}_2 \)?

IUPAC name \( [\text{CoCl}_2(\text{en})_2]\text{Cl} \)

Find the mass of an organic compound of molar mass 84, required to prepare 250 ml solution of molarity 0.4