Question

The type of bonds present in sulphuric anhydride are

• A. \(3\sigma\) and three \(p\pi-d\pi\)
• B. \(3\sigma\), one \(p\pi-p\pi\) and two \(p\pi-d\pi\)
• C. \(2\sigma\) and three \(p\pi-d\pi\)
• D. \(2\sigma\) and two \(p\pi-d\pi\)

Hint:

In \(SO_3\), there are always 3 sigma bonds. The \(\pi\) bonding is explained by resonance and \(p\pi-d\pi\) interactions.

Answer 1

The Correct Option is B

Step 1: Identify sulphuric anhydride.
Sulphuric anhydride is \(SO_3\).
Step 2: Structure and bonding of \(SO_3\).
In \(SO_3\), sulphur forms three \(S-O\) sigma bonds.
So number of sigma bonds:
\[ 3\sigma \]
Step 3: Nature of \(\pi\)-bonding.
In \(SO_3\), \(\pi\)-bonding involves overlap of oxygen \(p\)-orbitals with sulphur \(d\)-orbitals (\(p\pi-d\pi\)) and one bond has \(p\pi-p\pi\) character due to resonance.
Thus total:
- One \(p\pi-p\pi\) bond
- Two \(p\pi-d\pi\) bonds
Final Answer:
\[ \boxed{3\sigma,\;1(p\pi-p\pi),\;2(p\pi-d\pi)} \]