List of top Chemistry Questions

The half life of a radioactive nucleus is $50$ days. The time interval (t$_2-t_1$) between the time t$_2$ when $\frac{2}{3}$ ot it has decayed and the time $t_1$, when $\frac{1}{3}$ of it had decayed is

The geometry of ammonium ion is

The formation of molecular complex $BF_3 ??NH_3$ results in a change in hybridization of boron

The following sets of quantum numbers represent four electrons in an atom. (i) $n=4, \,l= 1$ $\quad$$\quad$(ii) $n=4,\, l=0$ (iii) $n = 3,\,l=2$$\quad$$\quad$ (iv) $n = 3,\,l= 1$ The sequence representing increasing order of energy, is

The element that does not show catenation among the following $p$-block elements is

The electron affinity of chlorine is $3.7\, eV. \,1$ gram of chlorine is completely converted to $Cl^-$ ion in a gaseous state. $(1\, eV = 23.06\, kcal\, mol^{-1})$. Energy released in the process is

The electrode potential E$_{\left(\frac{Zn^{2+}}{Zn}\right)}$ of a zinc electrode at 25$^{\circ}$C with an aqueous solution of 0.1M $ZnSO_4$ is (E$^{\circ}$$_{\left(\frac{Zn^{2+}}{Zn}\right)}$ = -0.76 V. Assume $\frac{2.303RT}{F} =$ 0.06 at 298 K)

The dissociation constant of a substituted benzoic acid at $25^{\circ}C$ is $1.0 \times 10^{-4}$. The $pH$ of $0.01 \,M$ solution of its sodium salt is

The difference between the reaction enthalpy change $\left( \Delta_{r}H\right)$ and reaction internal energy change $\left( \Delta_{r}U\right)$ for die reaction : $2C_{6}H_{6} \left(1\right) +15O_{2} \left(g\right) \to 12CO_{2} \left(g\right) + 6H_{2}O\left(1\right)$ at $300$ K is $\left(R=8.31 \,,mol^{-1}K^{-1}\right)$

The density of a solution prepared by dissolving $120\, g$ of urea (mol. mass = $60\, u$) in $1000 \,g$ of water is $1.15\, g/mL$. The molarity of this solution is :

The d-electron configurations of $Cr^{2+},Mn^{2+},Fe^{2+}$ and $Co^{2+}$ are $d^4, d^5, d^6$ and $d^7$ respectively. Which one of the following will exhibit the lowest paramagnetic behaviour? (Atomic no. $Cr=24, Mn=25, Fe=26, Co=27$).

The correct statement for both the processes of physisorption and chemisorption is

The conversion of benzene diazonium chloride to bromobenzene can be accomplished by

The chlorination of methane is an example of

Synthetic polymer bakelite can be prepared from following compounds

Square-planar geometry is shown by

Shape and hybridisation of $SO_2$ are

Select the correct order in relation with the bond length

Purple of cassius is a/an

Protein part of a Holoenzyme is called

Predict the products in the given reaction,

Peptization is a process in which

Oxidation number of $Cr$ in $Cr_{2} O^{2-}_{7}$ is

Number of isomers of CH

N?? bond length is minimum in