Introduction
The volatility of a liquid is influenced by its molecular structure and intermolecular forces. In this case, we compare the volatility of (CH₃)₂CO (acetone) and (CH₃)₂SiO (dimethylsiloxane).

Structure and Composition
- **(CH₃)₂CO (Acetone)**
- Acetone is a simple ketone with a carbonyl (C=O) functional group.
- The molecule has a relatively small size and a polar functional group, which allows for weak intermolecular forces like dipole-dipole interactions and Van der Waals forces.
- **(CH₃)₂SiO (Dimethylsiloxane)**
- Dimethylsiloxane is a silicone compound with a Si-O bond.
- The presence of silicon and oxygen results in a larger, more complex molecular structure with stronger intermolecular forces.

Intermolecular Forces
- **For Acetone**
- The dipole-dipole interactions due to the polar carbonyl group are significant yet relatively weak compared to hydrogen bonds.
- This allows acetone molecules to escape easily into the vapor phase, contributing to its high volatility.
- **For Dimethylsiloxane**
- Dimethylsiloxane exhibits stronger intermolecular interactions due to Si-O bonds, which create a more robust network of forces.
- This results in a higher boiling point and lower volatility, making it less likely to vaporize.

Conclusion
In summary, the volatility of (CH₃)₂CO is primarily due to its smaller size and weaker intermolecular forces, while (CH₃)₂SiO has stronger forces and a larger molecular structure, resulting in lower volatility.