List of top Chemistry Questions

The element with highest electronegativity after fluorine is:

Elements A and B have FCC and BCC structures respectively with unit cell edge length \( a = 3 \, \text{Å} \).
The number of atoms in 210 g of A = number of atoms in 594 g of B.
If density of A is \( 7 \, \text{g/cm}^3 \), what is the density of B?

The anions (A) of \( \text{C}_p\text{A}_q \) molecule form an fcc lattice. Cations (C) are positioned at the body center and half of the edge centers. The formula of the molecule is:

The product ‘Q’ of the following reactions is:

The correct statements with respect to halides of group 14 elements are:
(I) Both CCl4 and SiCl4 undergo hydrolysis.
(II) GeX4 is more stable than GeX2.
(III) PbX4 is less stable than PbX2.
(IV) Stability of dihalides decreases down the group.

Metal ‘M’ in the following reaction is: \[ 2 \text{MNO}_3 \rightarrow \text{M}_2\text{O} + 2\text{NO}_2 + \frac{1}{2}\text{O}_2 \]

The correct order of acidic nature of the following alkynes is:
I. \( \text{C}_2\text{H}_2 \)
II. \( (\text{CH}_3)_2\text{C}_2 \)
III. \( (\text{CH}_3)\text{C}_2\text{H} \)

The reaction of diborane in diethyl ether with X gives metal borohydride. X is a:

For the reaction \( A(g) + \frac{1}{2} B(g) \rightleftharpoons C(g) + \text{heat} \), the favorable conditions for the forward reaction are:

The \( K_a \) values of A, B, and C are \( 1.8 \times 10^{-4} \), \( 5 \times 10^{-10} \), and \( 3 \times 10^{-8} \), respectively.
The correct order of their acidic strength is:

The compound that is used in smoke screens is:

Which of the following is not a disproportionation reaction?

Maximum number of electrons possible with spin quantum number \(+\frac{1}{2}\) and principal quantum number \(n = 4\) in an atom is:

The combination of which of the following gives an ionic compound with maximum covalent character?

The tetra-atomic molecules/ions with different shapes are:

The number of valence electrons present in an element with atomic number 117 is:

In which of the following, the elements Al, B, Mg, and K are correctly arranged in the increasing order of their metallic character?

Which of the following reactions is not a disproportionation reaction?

Find the false statement for ideal gases:

The wavelength of the electron in the first orbit of hydrogen atom is \(3.3 \times 10^{-10} \, \text{m}\). The kinetic energy of the electron (in J) is: (Given: \( h = 6.6 \times 10^{-34} \, \text{Js}, \, m_e = 9.0 \times 10^{-31} \, \text{kg} \))

What does an oxidizing agent do?

If O₂ gas is bubbled through water at 303 K, the number of millimoles of O₂ gas that dissolve in 1 litre of water is_______. (Nearest integer)
(Given : Henry’s Law constant for O₂ at 303 K is 46.82 k bar and partial pressure of O₂ = 0.920 bar)
(Assume solubility of O₂ in water is too small, nearly negligible)

For diatomic molecules, the correct statement(s) about the molecular orbitals formed by the overlap to two $2 p_z$ orbitals is(are)