Chapter 17 - Quiz

Which of the following is a spontaneous change?

• Sugar dissolving in water

• Freezing of water at room temperature

• Diffusion of gas from low pressure to a high pressure

• Flow of heat from cold body to a hot body

What happens to the entropy when a solid melts?

• Entropy decreases

• Entropy remains the same

• Entropy increases

• Entropy cannot be determined

Which type of substances have lower entropy?

• Gases

• Solids

• Liquids

• Aqueous solutions

What is the entropy change of the system for the reaction 2Ca(s) + O₂(g) → 2CaO(s)?

• Increases

• Decreases

• Remains constant

• Can not be calculated

Which combination of ΔH and ΔS never has a spontaneous reaction? (Hint: ΔG = ΔH - TΔS)

• +ΔH and +ΔS

• -ΔH and +ΔS

• +ΔH and -ΔS

• -ΔH and -ΔS