Q3). 20 L diatomic ideal gas (Cv=2.5nR) expands from 300 K, 40 kPa to 3.5 kPa in three paths: (1) Isothermal reversible expansion; (2) Adiabatic reversible expansion; (3) Adiabatic expansion in the constant pressure of 3.5 kPa. Calculate , , in different paths.

Q4). 1 mol Zn is dissolved in sufficient dilute hydrochloric acid, and 1 mol H2 is produced under 291 K and 100 kPa. At the same time, 152 kJ heat is released. Calculate W and . The gas can be considered as an ideal gas.