List of top Chemistry Questions

Arrange the following halides in decreasing order of their reactivity towards dehydrohalogenation: 

Choose the correct statements from the following: I) In vapour phase, \( BeCl_2 \) exists as a chlorobridged dimer.
II) \( BeSO_4 \) is readily soluble in water.
III) \( BeO \) is completely basic in nature.
IV) \( BeCO_3 \), being unstable, is kept in the atmosphere of \( CO_2 \).
V) \( BeCO_3 \) is less soluble among all the carbonates of group 2 elements.
For the reaction at \( T(K) \), \( A_2(g) \rightleftharpoons B_2(g) \), \( K_c \) for the reaction at \( T(K) \) is 39.0. In a closed 1L flask, one mole of \( A_2(g) \) was heated to \( T(K) \). What is the concentration of \( B_2(g) \) at equilibrium (in mol L\(^{-1}\))?

Which of the following industries generate non-biodegradable wastes?

1) Cotton mills
(2) Paper mills
(3) Thermal power plants
(4) Textile factories

At high pressure and regulated supply of air, methane is heated with catalyst ‘X’ to give methanol and with catalyst ‘Y’ to give methanal. \( X \) and \( Y \) respectively are:

Which of the following orders is correct for the property given?

What is the percentage of carbon in the product 'Z' formed in the reaction? 

Given below are the two statements regarding chlorobenzene
Statement I: Chlorobenzene is less reactive than benzene towards electrophilic substitution due to the -I effect of chlorine.
Statement II: Because of the -I effect of chlorine, it is a meta directing group.
0.592 g of copper is deposited in 60 minutes by passing 0.5 amperes current through a solution of copper (II) sulphate. The electro chemical equivalent of copper (II) in g/C is:
The pK\(_a\) values of X, Y, Z respectively are 8.3, 7.1, 10.2. What are X, Y, Z?
Among the hydrides \( NH_3, PH_3, \) and \( BiH_3 \), the hydride with highest boiling point is \( X \) and the hydride with lowest boiling point is \( Y \). What are \( X \) and \( Y \) respectively?
At what temperature will the RMS velocity of sulfur dioxide molecules at 400 K be the same as the most probable velocity of oxygen molecules?
Observe the following compounds/ions: \[ H_3BO_3, \, [B(OH)_4]^-, \, BH_4^-, \, [BCI_3 \cdot NH_3], \, SiO_4^{2-} \] The number of compounds/ions with tetrahedral shape is:
The molar conductivity of 0.02 M solution of an electrolyte is \( 124 \times 10^{-4} \) S m\(^{2}\) mol\(^{-1}\). What is the resistance of the same solution (in ohms), kept in a cell of cell constant 129 m\(^{-1}\)?
Which of the following will have a spin-only magnetic moment of 2.86 BM?
If \(n\) and \(l\) represent the principal and azimuthal quantum numbers respectively, the formula used to know the number of radial nodes possible for a given orbital is:
The kinetic energy of electrons emitted, when radiation of frequency \( 1.0 \times 10^{15} \) Hz hits a metal, is \( 2 \times 10^{-19} \) J. What is the threshold frequency of the metal (in Hz)? (\( h = 6.6 \times 10^{-34} \) Js)

Identify the set, in which X and Y are correctly matched:

Match the following: 

At T(K), 0.1 moles of a non-volatile solute was dissolved in 0.9 moles of a volatile solvent. The vapour pressure of pure solvent is 0.9 . What is the vapour pressure (in ) of the solution? 

The standard enthalpy of combustion of C (graphite), H\(_2\) (g) and CH\(_3\)OH (l) respectively are \(-393\), \(-286\) and \(-726\) kJ mol\(^{-1}\). What is the standard enthalpy of formation of methanol?
Which of the following oxoacids of phosphorus has two P-H bonds?
Which of the following is correct statement?
Electromagnetic radiation has electric and magnetic field components. These two components:

Arrange the following in the increasing order of pKa values.