List of top Chemistry Questions

What is the percentage of free space in body centered cubic unit cell?

All substances that conduct electricity in aqueous solutions are called?

In acidic medium, $H_2O_2 $ changes $ Cr_2O_7^{2-} $ to $CrO_5 $ which has two (-O-O-) bonds. Oxidation state of Cr in $CrO_5 $ is

The hydrides of the first elements in groups $15 - 17$, namely $NH_3, H_2O$ and $HF$ respectively show abnormally high values for melting and boiling points. This is due to

To observe an elevation of boiling point of $0.05^?C$, the amount of solute (Mol. $Wt. = 100$) to be added to $100\, g$ of water $(K_b=0.5)$ is

Metal ion responsible for the Minamata disease is

The compound that will have a permanent dipole moment among the following is

The bond angle in $NF _{3}\left(102.3^{\circ}\right)$ is smaller than $NH _{3} (107.2 \left.^{\circ}\right)$. This is because of

The number of amino acids and number of peptide bonds in a linear tetrapeptide (made of different amino acids) are respectively

Two gases $X$ (Mol. Wt. $M_x$) and $Y$ (Mol. Wt. $M_Y; M_Y > M_x$) are at the same temperature T in two different containers. Their root mean square velocities are $C_X$ and $C_Y$ respectively. If the average kinetic energies per molecule of two gases $X$ and $Y$ are $E_x$ and $E_Y$ respectively, then which of the following relation (s) is (are) true?

When phenol is treated with $D_2SO_4/D_2O$, some of the hydrogens get exchanged. The final product in this exchange reaction is

In the reaction, $8 Al +3 Fe _{3} O _{4} \longrightarrow 4 Al _{2} O _{3}+9 Fe$ the number of electrons transferred from the reductant to the oxidant is

Which of the following hydrogen bonds are strongest in vapour phase?

Which of the following has an ester linkage?

Which of the following isomerism is shown by ethyl acetoacetate?

Among the elements from atomic number $1$ to $36$, the number of elements which have an unpaired electron in their $s$ subshell is

$0.44\, g$ of a monohydric alcohol when added to methyl magnesium iodide in ether liberates at $S.T.P.,$ $112\, cm^3$ of methane. With $PCC$ the same alcohol forms a carbonyl compound that answers silver mirror test. The monohydric alcohol is

$+CH_3MgBr ->[{\text{ether}}] A ->{[H_2O/H^+] B}$ The IUPAC name of 'B' is

The correct sequence of reactions to be performed to convert benzene into $m$-bromoaniline is

In which one of the pairs of ion given, there is an ion that forms a co-ordination compound with both aqueous sodium hydroxide and ammonia and an other ion that forms a co-ordination compound only with aqueous sodium hydroxide ?

(a) ${H_2 O_2 + O_3 -> H_2O + 2O_2}$ (b) ${H_2 O_2 + Ag_2O -> 2Ag + H_2O + O_2}$ Role of hydrogen peroxide in the above reactions is respectively -

The standard molar heat of formation of ethane, $CO_2$ and water are respectively $-21.1, -94.1$ and $-68.3\, kcal$. The standard molar heat of combustion of ethane will be

The bond angles of $NH _{3}, NH _{1}^{+}$and $NH _{2}^{-}$are in the order

Using the Gibbs energy change, $\Delta G^\circ = +63.3kJ$ , for the following reaction, $Ag_2CO_3 \rightleftharpoons 2Ag^+_{(aq)}+CO^{2^−}_{3(aq)}$ the $K_{sp}$ of $Ag_2CO_3(s)$ in water at $25^∘$C is ($R=8.314JK^{−1}mol^{−1}$)