Which of the following physical changes would be expected to provide a positive change in entropy , D S 0?
I. Compressing a gas until it liquefies.
II. Melting an ice-cube.
III. Heating a substance to a higher temperature.

Question

Which of the following physical changes would be expected to provide a positive change in entropy , D S > 0?
I. Compressing a gas until it liquefies.
II. Melting an ice-cube.
III. Heating a substance to a higher temperature.

Quizplus · Accepted Answer

Melting an ice-cube and heating a substance both involve an increase in the disorder of the molecules, leading to an increase in entropy (DS>0). Compressing a gas, however, involves a decrease in volume and an increase in order, leading to a decrease in entropy (DS<0). Therefore, only melting an ice-cube and heating a substance to a higher temperature would result in a positive change in entropy.

Which of the Following Physical Changes Would Be Expected to Provide