List of top Chemistry Questions

Which among the following species have the same number of electrons in its outermost as well as penultimate shell?

For a reaction $H _{2}+ I _{2} \rightleftharpoons 2 HI$ at $721\, K$, the value of equilibrium constant is $50$. If $0.5$ moles each of $H_{2}$ and $I_{2}$ is added to the system, the value of equilibrium constant will be:

$C_{6} H_{5}-C H=C H C H O \xrightarrow{X} C_{6} H_{5} C H=C H C H_{2} O H$ In the above sequence $X$ can be:

The ability of a given substance to assume two or more crystalline structure is called :

Number of isomers possible for $C_{4}H_{8}O$ is

Which of the following molecules has pyramidal shape?

What is the oxidation state of $P$ in $Ba(H_{2}PO_{2})_{2}$ ?

Which of the following is dihydric alcohol?

Which of the following oxide of nitrogen is most thermally stable?

Which of the following statements is incorrect?

Which one of the given transition metal ions is diamagnetic?

Which reaction is used for the preparation of acetophenone?

Which of the following element shows maximum valency?

Which of the following molecules has pentagonal bipyramidal shape?

The acidity of hydrides of $O , S , Se$, Te varies in the order :

The stability of complexes of $ C{{u}^{2+}},\,\,N{{i}^{2+}},\,\,C{{o}^{2+}} $ and $ F{{e}^{2+}} $ varies in the order:

The bond order of $ O_{2}^{+},\,\,{{O}_{2}},\,\,O_{2}^{2-} $ and $ O_{2}^{-} $ varies in the order:

Molecular orbital electronic configuration for $' X'$ anion is : $K K^{*}(\sigma 2 s)^{2}\left(\sigma^{*} 2 s\right)^{2}\left(\pi 2 p_{x}\right)^{2}\left(\pi 2 p_{y}\right)^{2}\left(\sigma 2 p_{z}\right)^{2}$ $\left(\pi^{*} 2 p_{x}\right)^{1}$. The anion ' $X$' is :

The relative Lewis acid character of boron trihalides is in the order:

Which of the following statements is incorrect?

The mass of a photon with wavelength $ 3.6\,??$ is:

An electron with values $4, 2, -2$ and $+1/2$ for the set of four quantum numbers $ n,\,\,l,\,\,{{m}_{l}} $ and $ s $ respectively, belongs to:

Which of the following compounds is the strongest acid?

Which of the following compounds has the highest boiling point?

Which of the following acts as pickling agent?