Question

Identify the correct statements from the following
\[ \text{(I) } SnCl_2 \text{ is ionic, but } SnCl_4 \text{ is covalent in nature} \] \[ \text{(II) All linear diatomic molecules have zero dipole moment} \] \[ \text{(III) Both } NO \text{ and } O_2 \text{ are paramagnetic} \]

• A. (I) and (II) only
• B. (I) and (III) only
• C. (II) and (III) only
• D. (I), (II) and (III)

Hint:

Paramagnetic species contain unpaired electrons. Also, linear shape alone does not guarantee zero dipole moment; the molecule must be symmetrical or homonuclear.

Answer 1

The Correct Option is B

Step 1: Check statement (I).
\(SnCl_2\) contains tin in the \(+2\) oxidation state.
It has more ionic character compared to \(SnCl_4\).
In \(SnCl_4\), tin is in the \(+4\) oxidation state and has higher polarising power.
Due to greater polarisation of chloride ions, \(SnCl_4\) becomes covalent in nature.
Therefore, statement (I) is correct.

Step 2: Check statement (II).
A linear diatomic molecule has zero dipole moment only when both atoms are identical.
For example, \[ H_2,\ O_2,\ N_2 \] have zero dipole moment.
But heteronuclear diatomic molecules such as \[ HCl,\ CO,\ NO \] may have non-zero dipole moment.
Therefore, all linear diatomic molecules do not have zero dipole moment.
Hence, statement (II) is incorrect.

Step 3: Check statement (III).
\(O_2\) is paramagnetic because it contains unpaired electrons in antibonding molecular orbitals.
\(NO\) is also paramagnetic because it has an odd number of electrons and contains one unpaired electron.
Therefore, statement (III) is correct.

Step 4: Final conclusion.
The correct statements are \[ \text{(I) and (III) only} \] Hence, \[ \boxed{\text{(I) and (III) only}} \]