List of top Chemistry Questions

Bond dissociation enthalpy of ${H_2, Cl_2}$ and $HCl$ are $434, 242$ and ${431 \, kJmol^{- 1}}$ respectively. Enthalpy of formation of $HCl $ is
For the gas phase reaction, ${PCl_{5} (g) <=> PCl_{3} (g) + Cl_{2} (g)}$ which of the following conditions are correct ?
The correct order of decreasing second ionisation enthalpy of Ti(22), V(23), Cr(24) and Mn(25) is
The order of a reaction for an esterification process is
How many electrons are present in 3d orbital of tetrahedral $K_2 [NiCl_4]$ complex?
During a redox titration involving a solution containing $Fe ^{2+}$ ions against $MnO _{4}^{-}$in the presence of excess of $H ^{+}$ions, the number of electrons that gets transferred is.
Equimolar solutions of the following were prepared in water separately. Which one of the solutions will record the highest pH ?
Which one of the following is an amine hormone?
What is the chemical name of the vitamin $B_{12}$ ?
Conversion of chlorobenzene to phenol involves
When chlorine reacts with dil. $NaOH$ under cold conditions, the oxidation state of chlorine changes from zero to
How many stereoisomers does this molecule have? $CH_3CH = CHCH_2CHBrCH_3$
The relative reactivities of acyl compounds towards nucleophilic substitution are in the order of
A strong base can abstract an $\alpha$-hydrogen from
In a given shell the order of screening effect is
In transforming $0.01$ mole of $PbS$ to $PbSO _{4}$, the volume of ' $10$ volume' $H _{2} O _{2}$ required will be
Number of moles of $MnO^{-}_4$ required to oxidise one mole of ferrous oxalate completely in acidic medium will be
The degree of dissociation of $XY$ in case of following reaction is found to be $ 0.4 $ from vapour density measurement. If the observed vapour density of $X Y$ be $100$ then its molecular weight is $ XY\to X+Y $
Amines behave as
An element with atomic number $21$ is a
The angular shape of ozone molecule $ (O_3 )$ consists of
In the reaction; $Fe ( OH )_{3( s )} \rightleftharpoons Fe ^{3+}{ }_{( aq )}+3 OH _{\text {(aq) }}^{-}$, if the concentration of $OH ^{-}$ ions is decreased by $\frac{1}{4}$ times, then the equilibrium concentration of $Fe ^{3+}$ will increase by,
The value of equilibrium constant of the reaction, $ HI(g) \rightleftharpoons \frac{1}{2} H_2 (g) + \frac{1}{2} I_2 (g)\, \, is\, \, 8.0 $ . The equilibrium constant of the reaction, $ H_2 (g) + I_2 (g) \rightleftharpoons 2HI(g) $ Will be
For the reaction $Fe_2O_3 +3CO \rightarrow 2Fe + 3CO_2$ the volume of carbon monoxide required to reduce one mole of ferric oxide is
The increasing order of the rate of HCN addition to compounds A-D is : (A) HCHO $(B)CH_{3} COCH_{3}$ $\left(C\right)phCOCH_{3}$ $\left(D\right)phcoph$