Question

In which form styrene exists at room temperature?

• A. Liquid
• B. Solid
• C. Gas
• D. Pseudo solid

Hint:

Most simple aromatic hydrocarbons are liquids at room temperature.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
The physical state of a substance at room temperature ($25^{\circ}\text{C}$) depends on its molecular weight and the strength of the intermolecular forces (like van der Waals forces).
Step 3: Detailed Explanation:
1. Styrene (ethenylbenzene) has the formula $C_{6}H_{5}CH=CH_{2}$.
2. It is an aromatic hydrocarbon with a molecular weight of approximately $104\text{ g/mol}$.
3. It has a melting point of $-30.6^{\circ}\text{C}$ and a boiling point of $145^{\circ}\text{C}$.
4. Since room temperature ($25^{\circ}\text{C}$) lies between its melting point and boiling point, styrene exists as a liquid at room temperature.
5. It is an oily, colorless liquid with a sweet, floral odor, although aged samples may appear yellowish.
Step 4: Final Answer:
Styrene exists as a liquid at room temperature.