During an isothermal and reversible process, 1 mole of helium gas, initially having a velocity distribution probability f(v), expands to occupy double its original volume. What is the change in the velocity distribution probability due to the isothermal expansion?
A jeweler heats an 8 g gold ring to 500 °C and places it on his workbench to cool down naturally to 30 °C. What is the entropy variation of the gold ring while it cools?
An ice cream cake at -18 °C left out in the kitchen melts within 30 minutes. The temperature in the kitchen is 30 °C. The kitchen-ice cream system is considered isolated, and the kitchen temperature is assumed constant. Without using calculations, state if this is a reversible or an irreversible process and identify the sign of the entropy variation.
Cryotherapy, a common method for treating athletes' injuries, works by filling a large tub with 100 kg of cold water at 10 °C and pouring in 1 kg of ice at 0 °C. The cold water is being cooled further by ice. i) Is this a reversible or irreversible process, and what is the sign of the entropy variation (ΔS)? Do not use calculations.
What change in entropy (ΔS) occurs when a butter cube of mass 6.9 g at 35 °C is totally melted? Butter melts at 35 °C and has a latent heat of fusion of 60 J/g.
