gram shows how entropy varies with temperature for a substance that is a gas at the highest temperature shown. a plot of entropy on the y axis versus the temperature in kelvin on the x axis. the entropy and the temperature are initially 0. as the temperature increases, the entropy increases linearly. at a point some distance from the initial point, the entropy increases as the temperature remains constant. this portion is labeled 1. the entropy then continues to increases linearly as the temperature increases. at a third point some distance from the second point, the entropy again increases as the temperature remains constant. this portion is labeled 2. the entropy then increases linearly again as the temperature increases. segment 2 is larger than segment 1. what process corresponds to the entropy increase along the vertical segment labeled 1? the melting of the solid substance to a liquid. the boiling of the liquid substance to a gas. the warming of the liquid substance to its boiling point. the warming of the gaseous substance to its final temperature. the warming of the solid substance to its melting point.

Answer

the melting of the solid substance to a liquid.

Identify the options. A: The options are: the melting of the solid substance to a liquid. the boiling of the liquid substance to a gas. the warming of the liquid substance to its boiling point. the warming of the gaseous substance to its final temperature. the warming of the solid substance to its melting point.
Eliminate the incorrect options. A: This segment shows a constant temperature and an increase in entropy, which is characteristic of a phase change. Therefore, we can eliminate options 3, 4, and 5. Segment 2 is larger than segment 1, indicating that the phase change represented by segment 1 requires more energy than the phase change represented by segment 2. This suggests that the substance is changing from a solid to a liquid, which requires more energy than changing from a liquid to a gas. Therefore, we can eliminate option 2. This leaves option 1, 'the melting of the solid substance to a liquid,' as the correct answer.