List of top Chemistry Questions

The hybridization of P exhibited in \(PF_5\) is \(sp_xd_y\). The value of y is _____ .
4.0 L of an ideal gas is allowed to expand isothermally into vacuum until the total volume is 20 L. The amount of heat absorbed in this expansion is ____ L atm.
The vapour pressures of two volatile liquids A and B at 25°C are 50 Torr and 100 Torr, respectively. If the liquid mixture, contains 0.3 mole fraction of A, then the mole fraction of liquid B in the vapour phase is \(\frac {x}{17}\). The value of x is _____.
The solubility product of a sparingly soluble salt \(A_2X_3\) is \(1.1 × 10^{–23}\). If the specific conductance of the solution is \(3×10^{–5}\) S m–1, the limiting molar conductivity of the solution is \(x×10^{–3}\) S m2 mol–1. The value of x is _______.
The quantity of electricity of Faraday needed to reduce \(1\) mol of \(Cr_2O_7^{2-}\) to \(Cr^{3+}\) is
For a first order reaction \(A → B\), the rate constant, \(k = 5.5×10^{–14}s^{–1}\). The time required for 67% completion of reaction is \(x×10^{–1}\) times the half life of reaction. The value of \(x\) is _____. (Nearest integer)
Number of complexes which will exhibit synergic bonding amongst, \([Cr(CO)_6]\), \([Mn(CO)_5]\) and \([Mn_2(CO)_{10}]\) is ________.
lf the work function of a metal is 6.63 × 10–19 J, the maximum wavelength of the photon required to remove a photoelectron from the metal is ______ nm. (Nearest integer)
[Given : h = 6.63 × 10–34 J s, and c = 3 × 108 m s–1]
Which amongst the following is not a pesticide?
A sugar ‘X’ dehydrates very slowly under acidic conditions to give furfural which on further reaction with resorcinol gives the coloured product after some time. Sugar ‘X’ is
sugar ‘X’ dehydrates very slowly under acidic condition
A mixture of hydrogen and oxygen contains 40% hydrogen by mass when the pressure is 2.2 bar. The partial pressure of hydrogen is _______ bar. (Nearest integer)
The wavelength of an electron and a neutron will become equal when the velocity of the electron is x times the velocity of neutron. The value of x is ______. (Nearest integer)
(Mass of electron is 9.1 × 10–31 kg and mass of neutron is 1.6 × 10–27 kg)
2.4 g coal is burnt in a bomb calorimeter in excess of oxygen at 298 K and 1 atm pressure. The temperature of the calorimeter rises from 298 K to 300 K. The enthalpy change during the combustion of coal is –x kJ mol–1. The value of x is ______.(Nearest integer)
(Given : Heat capacity of bomb calorimeter is 20.0 kJ K–1. Assume coal to be pure carbon)
When 800 mL of 0.5 M nitric acid is heated in a beaker, its volume is reduced to half and 11.5 g of nitric acid is evaporated. The molarity of the remaining nitric acid solution is \(x × 10^{–2} M\). (Nearest integer)
(Molar mass of nitric acid is 63 g mol–1)
At \(298\ K\), the equilibrium constant is \(2 × 10^{15}\) for the reaction:
\(Cu(s)+2Ag+(Aq)⇌Cu^{2+}(aq)+2Ag(s)\)
The equilibrium constant for the reaction:
\(\frac 12Cu^{2+}(aq)+Ag(s)+(Aq)⇌\frac 12Cu(s)+Ag^+(aq)\) is \(x \times10^{-8}\).
The value of \(x\) is ______ . (Nearest integer)
The amount of charge in F (Faraday) required to obtain one mole of iron from \(Fe_3O_4\) is ______ . (Nearest integer)
For a reaction \(A → 2B + C\) the half lives are 100 s and 50 s when the concentration of reactant A is 0.5 and 1.0 mol L–1, respectively. The order of the reaction is ______ .(Nearest integer)
The difference between spin only magnetic moment value of \([Co(H_2O)_6]Cl_2\) and \([Cr(H_2O)_6]Cl_3\) is ________ .
In the presence of sunlight, benzene reacts with CI2 to give product X. The number of hydrogens in X is _________.

Consider the species
\(CH_4,NH_{4}^+ and BH_{4}^−.\)
Choose the correct option with respect to these species.

4.0 moles of argon and 5.0 moles of PCl5 are introduced into an evacuated flask of 100 litre capacity at 610 K. The system is allowed to equilibrate. At equilibrium, the total pressure of mixture was found to be 6.0 atm. The Kp for the reaction is
 [Given : R = 0.082 L atm K–1 mol–1 ]
A 42.12% (w, v) solution of NaCl causes precipitation of a certain sol in 10 hours. The coagulating value of NaCl for the sol is
[Given : Molar mass : Na = 23.0 g mol–1; Cl = 35.5 g mol–1]

Match List-I with List-II
 

 List-I Ore List-II Composition
A.SideriteI.FeCO3
B.MalachiteII.CuCO3. Cu(OH)2
C.SphaleriteIII.ZnS
D.CalamineIV.ZnCO3


Choose the correct answer from the options given below:

Given below are two statements.
Statement-I: In CuSO4.5H2O, Cu-O bonds are present.
Statement-II: In CuSO4.5H2O, ligands coordinating with Cu(II) ion are O-and S-based ligands.
In the light of the above statements, choose the correct answer from the options given below:

Number of lone pair(s) of electrons on central atom and the shape of BrF3 molecule respectively, are