List of top Chemistry Questions

The extra stability of half-filled subshell is due to
(A) Symmetrical distribution of electrons
(B) Smaller coulombic repulsion energy
(C) The presence of electrons with the same spin in non-degenerate orbitals
(D) Larger exchange energy
(E) Relatively smaller shielding of electrons by one another
Identify the correct statements
For electron in '2s' and '2p' orbitals, the orbital angular momentum values, respectively are :
Which of the following has the highest ionization energy?
Which element has the smallest atomic radius among the following?
The orbital with number of total nodes as 3 and angular nodes as 3 is
Match the following
Choose the incorrect statement from the following:
The ratio of wavelengths of first line (\( n_2 = 3 \)) and second line (\( n_2 = 4 \)) of Balmer series of hydrogen spectrum is
The ratio of wavelengths of first line (\( n_2 = 3 \)) and second line (\( n_2 = 4 \)) of Balmer series of hydrogen spectrum is
The number of d-electrons in Fe2+ (Z = 26) is not equal to:

Which of the following represents the wavelength of spectral line of Balmer series of He$^+$ ion? (R = Rydberg constant, n $>$ 2)

In Hydrogen atom, an electron jumped from an orbit of radius 2592.1 pm to another orbit of radius 211.6 pm. What is the energy difference (in J) between these two states?
According to Bohr's theory of hydrogen atom, the approximate angular momentum of electron in H atom in the ground state is ($h = 6.62 \times 10^{-34}$ Js):
Observe the elements from H (Z=1) to Ca (Z=20). How many elements have no unpaired electrons in their ground state?
Observe the elements from H(Z=1) to Ca(Z=20). The number of elements with 1, 2 and 3 unpaired electrons in their ground state is respectively

An element has two isotopes having atomic masses 10 and 15 u, respectively. If the percent abundance of lighter isotopes is 80%, then the average atomic mass of the element is:

Which of the following molecules has a trigonal planar molecular geometry?
The hybridization in SF\(_6\) molecule is:
Which of the following has the highest lattice energy?
The shape of PCl\(_5\) molecule is:
The hybridization of carbon in diamond is:

0.01 mole of an organic compound (X) containing 10% hydrogen, on complete combustion, produced 0.9 g H₂O. Molar mass of (X) is ___________g mol\(^{-1}\).

(ii) Account for the following:
(I) We cannot determine the order of a reaction by taking into consideration the balanced chemical equation.
(II) A bimolecular reaction may become kinetically first order under a specified condition.
The functional group in ethers is:
The order of reactivity of alcohols towards dehydration is: