List of top Chemistry Questions

The reaction, $2 A(g)+B(g) \rightleftharpoons 3 C(g)+D(g)$ is begun with the concentrations of $A$ and $B$ both at an initial value of $1.00\, M .$ When equilibrium is reached, the concentration of $D$ is measured and found to be $0.25\, M$. The value for the equilibrium constant for this reaction is given by the expression

The pressure exerted by $6.0 \,g$ of methane gas in a $0.03\, m ^{3}$ vessel at $129^{\circ} \,C$ is (Atomic masses: $C =12.01, \,H =1.01$ and $\left.R=8.314\, JK ^{-1} \,mol ^{-1}\right)$

Some statements about heavy water are given below. (i) Heavy water is used as moderator in nuclear reactors (ii) Heavy water is more associated than ordinary water (iii) Heavy water is more effective solvent than ordinary water Which of the above statements are correct?

The order of reactivity of phenyl magnesium bromide $(PhMgBr)$ with the following compounds

Some of the properties of the two species, $NO _{3}^{-}$and $H _{3} O ^{+}$are described below. Which one of them is correct?

$ pH $ of a saturated solution of $ Ba(OH)_2 $ is $12$ . The value of solubility product $ K_({sp} )$ of $ Ba(OH)_2 $ is

The correct set of four quantum numbers for the outermost electron of sodium ($Z = 11$) is

The carbon-carbon bond distance in benzene is

The vapour pressure of due to

The vapour pressures of two liquids $A$ and $B$ in their pure states are in the ratio of $1 : 2$. A binary solution of $A$ and $B$ contains $A$ and $B$ in the mole proportion of $1 : 2$. The mole fraction of $A$ in the vapour phase of the solution will be

Vapour pressure of chloroform ${(CHCl_3)}$ and dichloromethane ${(CH2Cl2)}$ at $25^{\circ}C$ are 200 mmHg and 41.5 mm Hg respectively. Vapour pressure of the solution obtained by mixing 25.5 g of ${CHCl_3}$ and 40 g of ${CH2Cl2}$ at the same temperature will be: (Molecular mass of ${CHCl_3}$ = 119.5 u and molecular mass of ${CH2Cl2 = 85 \, u}$)

The enthalpy of fusion of water is $1.435\, kcal/mol.$ The molar entropy change for the melting of ice at $0^{\circ}C$ is :

For real gases van der Waals equation is written as $\bigg( p + \frac{an^2}{V^2} \bigg) (V - nb) = nRT$ Where 'a' and 'b' are van der Waals constants . Two sets of gases are : (I)${ O2, CO2, H2}$ and $He$ (II) ${CH4, O2}$ and ${H2}$ The gases given in set-I in increasing order of 'b' and gases given in set-II in decreasing order of 'a', are arranged below. Select the correct order from the following :

The secondary valency of platinum in tetraamminedichloroplatinum $(IV)$ chloride is

A first order reaction is $60\%$ complete in $20$ minutes. How long will the reaction take to be $84\%$ complete ?

$20\, mL$ of methane is completely burnt using $50\, mL$ of oxygen. The volume of the gas left after cooling to room temperature is

The volume of $0.1\, M$ oxalic acid that can be completely oxidized by $20\, ml$ of $0.025 \, M \, KMnO_4$ solution is

Impossible orbital among the following is

The total number of electrons in $18\, ml$ of water (density $= 1\, g \,ml^{-1} $) is

Which of the following is a negatively charged bidentate ligand ?

The atomic number of cobalt is $27$. The $EAN$ of cobalt in $Na_3 [Co(NO_2)_4Cl_2]$ is

Fructose reduces Tollen's reagent due to

The correct IUPAC name of the following compound is

Which of the following solutions is an example of negative deviation from Raoult�s law?

All colloidal dispersions have