List of top Chemistry Questions

The wave number of the limiting line in Lyman series of hydrogen is 109678 $cm^{-1}$. The wave number of the limiting line in Balmer series of $He^{+}$ would be :

The most likely protonation site in the following molecule is

Aniline reacts with phosgene and $KOH$ to form

$N_2$ and $O_2$ are converted into mono anions, $N_2^{-}$ and $O_2^{-}$ respectively. Which of the following statements is wrong ?

Which of the following ions can be separated by a $NH_4OH$ in presence of $NH_4Cl$

The correct order of magnetic moments (spin only values in B.M.) is:

An elemental crystal has a density of $8570 \,kg / m ^{3}$. The packing efficiency is $0.68$. The closest distance of approach between neighbouring atom is $2.86 \,?$. What is the mass of one atom approximately?

The ratio of oxidation states of $Cl$ in potassium chloride to that in potassium chlorate is

Which of the following among alkali metal is most reactive ?

Which form coloured salts :

The volume strength of $1.5 \, N \, H_2O_2$ solution is

Peptisation involves

The equivalent conductivity of a solution containing $2.54\, g$ of $CuSO _{4}$ per $L$ is $91.0\, W ^{-1} cm ^{2} eq ^{-1}$. Its conductivity would be

The solubility product of $Ag _{2} CrO _{4}$ is $32 \times 10^{-12}$. What is the concentration of $CrO _{4}^{-}$ions in that solution?

The rate constant for forward reaction and backward reaction of hydrolysis of ester are $1.1 \times 10^{-2}$ and $1.5 \times 10^{-3}$ per minute respectively. Equilibrium constant for the reaction is $CH _{3} COOC _{2} H _{5}+ H _{2} O \rightleftharpoons CH _{3} COOH + C _{2} H _{5} OH$

One mole of $PCl_5$ is heated in a closed 2 $dm^3$ vessel. At equilibrium 40% $PCl_5$ is dissociated. Calculate the equilibrium constant.

The correct order of oxidising power is : $VO_2^+$ $< Cr_2O_7^{2-} < MnO_4^-$ The oxidation state of $Mn$ is $+7$.

In the presence of peroxide, $HCl$ and $HI$ do not give anti-Markownikoff' s addition to alkenes because :

Considering the basic strength of amines in aqueous solution, which one has the smallest $pK_b$ value?

Conversion of benzene diazonium chloride to chloro benzene is an example of which of the following reactions ?

Amongst $LiCl, RbCl, BeCl_2$ and $MgCl_2$ the compounds with the greatest and the least ionic character, respectively are :

Which one of the following molecules is paramagnetic ?

In S$_N$2 reactions, the correct order of reactivity for the following compounds $CH_3Cl,CH_3CH_2Cl, (CH_3 )_2CHCl$ and (CH$_3 )_3CCl$ is

Which one of the following substituents at para-position is most effective in stabilizing the phenoxide ion ?

Which one of the following compounds will not be soluble in sodium bicarbonate?