Question

The diagram below shows the melting and boiling points of four different substances. Which substance is a solid at ${-40}^{\circ }C$ and a gas at ${120}^{\circ }C$?

• A. A
• B. B
• C. C
• D. D

Answer 1

The correct option is B B

Melting point of substance B is $-{20}^{o}C$, thus it remains in solid form at $-{40}^{o}C$. Also, boiling point of substance B is ${60}^{o}C$, thus it remains in gaseous form at ${120}^{o}C$.