Which of the following is steam volatile?

A. Nitrobenzene

B. Aniline

C. Both A and B

D. Neither A nor B

To determine which of the given compounds is steam volatile, we need to understand what steam volatility means. Steam volatility refers to the ability of a substance to vaporize in the presence of steam or at elevated temperatures. Generally, compounds that are more volatile have lower boiling points and can easily transition from liquid to gas. Let's analyze the two compounds you've mentioned: nitrobenzene and aniline.

Nitrobenzene

Nitrobenzene is an aromatic compound with the formula C₆H₅NO₂. It has a relatively high boiling point of about 210 °C. While it can evaporate, its high boiling point indicates that it is not particularly steam volatile. In practical terms, nitrobenzene does not readily vaporize in steam, making it less likely to be considered steam volatile.

Aniline

Aniline, on the other hand, is an amine with the formula C₆H₅NH₂. It has a lower boiling point of approximately 184 °C compared to nitrobenzene. This lower boiling point suggests that aniline is more likely to vaporize when exposed to steam. In fact, aniline can be more readily distilled and is known to have some degree of volatility.

Comparative Analysis

• Nitrobenzene: High boiling point (210 °C), less steam volatile.
• Aniline: Lower boiling point (184 °C), more steam volatile.

Given this information, we can conclude that aniline is the more steam volatile compound when compared to nitrobenzene. Therefore, the correct answer to your question is:

Final Answer

B. Aniline

In summary, while both compounds can exist in vapor form, aniline's lower boiling point makes it the more steam volatile of the two. This understanding is crucial in applications such as distillation and separation processes in chemistry, where the volatility of compounds plays a significant role in their behavior under heat and pressure.