Question

question 20 (5 points)
so₃ is a covalent compound with no lone pairs on the central s atom. whats the structure of a molecule of so₃? is an so₃ molecule polar or non - polar?
a) trigonal pyramidal, non - polar
b) trigonal planar, polar
c) trigonal planar, non - polar
d) trigonal pyramidal, polar

Explanation:

• Molecular Structure:
• For \(SO_3\), using VSEPR (Valence - Shell Electron - Pair Repulsion) theory. The central \(S\) atom has \(3\) bonding pairs and \(0\) lone pairs. The general formula for molecular geometry when \(AX_nE_m\) (where \(A\) is the central atom, \(X\) is the surrounding atom, \(E\) is the lone pair) is \(AX_3E_0\). The electron - pair geometry and molecular geometry for \(AX_3E_0\) is trigonal planar.
• Polarity:
• The \(S - O\) bonds are polar (since \(O\) is more electronegative than \(S\)). But in \(SO_3\), due to its trigonal planar symmetry, the bond dipoles cancel each other out. A non - polar molecule is one where the overall dipole moment is zero.

Answer:

C. Trigonal planar, non - polar