Chemical Bonding and Atomic Structure MCQs for NEET — Chemistry Questions with Answers

The bond length of a molecule is inversely proportional to the bond order. The bond orders for $O_2$, $H_2O_2$, and $O_3$ are 2, 1, and 1.5 respectively. Therefore, the bond length order is: $H_2O_2 extgreater O_3 extgreater O_2$.

A sigma (σ) bond is generally stronger than a pi (π) bond. The sigma bond is formed by the end-to-end overlap of atomic orbitals, which allows for a stronger overlap compared to the side-to-side overlap of the pi bond. Therefore, the statement 'σ bond is weaker than π bond' is incorrect.

$S^{2-}$ (sulfide ion) is not paramagnetic because it has no unpaired electrons. Paramagnetism arises due to the presence of unpaired electrons, which are absent in $S^{2-}$. Hence, $S^{2-}$ is diamagnetic.

SiCl₄ (Silicon tetrachloride) has a tetrahedral structure. For a molecule or ion to be isostructural with SiCl₄, it must also have a tetrahedral geometry. PO₄^3- (Phosphate ion), NH₄⁺ (Ammonium ion), and SO₄^2- (Sulfate ion) all have tetrahedral structures. However, SCl₄ (Sulfur tetrachloride) has a seesaw shape due to the presence of one lone pair on sulfur, and thus it is not isostructural with SiCl₄.

In crystalline lattice of diamond, each crbon atom is linked to four other carbon atoms tetrahedrally by using sp3 - hydbrid orbitals giving rise to a rigid there dimensional network of carbon atom for this reason, diamond is very hard.Graphite, has hexagonal layer structure in which each carbon atom is linked to three other carbon atoms by using sp2 hybrid orbitals. The hexagonal layer in graphite are held together by weak Van-der waal's forces. So graphite is soft.

The bond angle decreases as we move down the group in the periodic table due to increasing atomic size and decreasing bond pair-bond pair repulsion. Thus, the bond angle is minimum for $ H_2 Te $.

The shape of $O_2F_2$ (dioxygen difluoride) is similar to that of $H_2O_2$ (hydrogen peroxide). Both molecules have a non-linear (bent) structure due to the presence of lone pairs of electrons on the oxygen atoms, leading to a skewed or twisted shape.

The bonding in HCl is polar covalent. This is because chlorine (Cl) is more electronegative than hydrogen (H), resulting in an unequal sharing of electrons. This creates a dipole moment, with a partial negative charge on the chlorine atom and a partial positive charge on the hydrogen atom.

The melting point of an ionic compound is largely determined by the strength of the ionic bonds holding the lattice together. Among the given options (NaF, NaCl, NaBr, NaI), NaF has the highest melting point because it has the maximum ionic character. This is due to the high electronegativity of fluorine which leads to a strong electrostatic attraction between the sodium and fluoride ions, resulting in a high melting point.