**Otto and Diesel engines, Gibbs’ phase rule and chemical potential;**

Questions:

**Q 1. **What are the conditions for the change in temperature of a van der Waals gas passing through a porous plug? Prove that the ideal gas passing through the porous plug does not show any change in temperature. **[10 Marks]**

**Q 2. **one mole of gas obeys the equation of state: $(P+\frac a {v^2})(v-b)=RT$ where $v$ is the molar volume and $a$ and $b$ are constants. show that the internal energy of the gas increases as volume increases, with the temperature remaining constant. **[10 Marks]**

Video Solution at 11 pm