List of top Chemistry Questions

Molar enthalpy change for melting of ice is $6\, kJ / mol$. Then the internal energy change (in $k J / mol$ ) when $1$ mole of water is converted into ice at $1$ atm at $0^{\circ} C$ is Empty QImg

Which of the following options represents the correct bond order ?

How does the electron gain enthalpies vary across a period and down a group?

The species which cannot serve as an initiator for the free radical polymerisation, is

Among $P, S, Cl, F$, the elements with most negative and least negative electron gain enthalpy respectively, are

If the solubility of a sparingly soluble salt $AX _{2}$ is $s\, mol / L$, the solubility product is

The number of $Na$ atom in $46\, g \,Na$ (atomic weight of $Na= 23$) is

Nylon is a

Among second period elements/the correct order for first ionisation enthalpy is

$H A$ is a weak acid. At $25^{\circ} C$, the molar conductivity of $0.02\, M\, H A$ is $150\, \Omega^{-1} cm ^{2} mol ^{-1}$. If its $\Lambda_{ m }^{ o }$ is $300\, \Omega^{-1} cm ^{2} mol ^{-1}$, then equilibrium constant of $H A$ dissociation is

$K_{p} / K_{c}$ for the reaction $A(g)+2 B_{2}(g) \rightleftharpoons A B_{2}(g)$ is

n-hexane on heating to $773 \,K$ at $10-20$ atmospheric pressure in the presence of oxides of vanadium supported over alumina, yields

A gas at high temperature is cooled. The highest temperature at which liquefaction of gas first occurs is called

The compound formed upon combustion of potassium metal in excess air is

The number of tetrahedral and octahedral void per unit cell of cubic closed packed structure is

In an acidified aqueous solution of $Mn ^{2+}, Ni ^{2+}, Cu ^{2+}$ and $Hg ^{2+}$ ions, $H _{2} S$ gas was passed. Precipitates are

When the following amide is treated with $Br_{2}/KOH$, it gives

One mole of NaCl contains 6.023 ??10 molecules of sodium chloride. 58.5 g of NaCl also contains 6.023 ??10 molecules of NaCl.

A gas such as carbon monoxide would be most likely to obey the ideal gas law at :

Decreasing order of stability of $O_2, O^-_2, O_2^+ $ and ${ O_2^{2-}}$ is :

In which of the following pairs, both the species are not isostructural ?

Assuming complete ionization, same moles of which of the following compounds will require the least amount of acidified ${KMnO4}$ for complete oxidation ?

The number of water molecules is maximum in :

Glycogen is

Which of the following compounds is responsible for depletion of ozone layer?