Question

Nitrobenzene at room temperature is
A. Gas
B. Liquid
C. Solid
D. Solution

Answer 1

Hint: Nitrobenzene as compared to benzene is more stable and less reactive. Benzene has a very low melting point (5.5 °C) and boiling point (8.8 °C). Benzene easily evaporates with some initiation thus, easily changing its state, gaseous.

Complete Step by Step Solution:
Nitrobenzene is less reactive towards electrophilic substitution reaction as compared to benzene because nitrobenzene contains nitrogen which is directly attached to oxygen atom where oxygen atom is more electronegative element as compared to nitrogen. Thus, attract all the electron density towards itself from the ring and make the ring less available towards electrophile attack or can say, make the ring less reactive towards electrophilic reaction. Whereas in benzene there is no electronegative element attached to it, thus, it can easily show electrophilic substitution reaction.

Thus, nitrobenzene is less reactive or more stable due to the large number of resonance structures as compared to benzene. Due to this, its melting and boiling point will be more than benzene which is 5.7°C (Melting point) and 210°C (Boiling Point).

As Benzene easily evaporates at room temperature with some initiation, nitrobenzene will be liquid (pale yellow liquid) at room temperature.
Thus, the correct option is B.

Note: Nitrobenzene is very unreactive and also very stable but still liquid at room temperature because benzene in nitrobenzene which has very low melting and boiling point and after nitration nitrobenzene melting and boiling point increases but not to much extend. Thus, it is liquid at room temperature.