true or false

1. Diesel fuel has a higher energy content than gasoline. 2. The enthalpy of formation is zero at OK and 1 atm. FALSE 3. The entropy changes of a Carnot cycle starting and ending at the same state is zero 4. The entropy changes for an irreversible process starting and ending at the same state is zero. 5. The entropy of a system is always positive or zero. 6. The second law is conservation of entropy principle. 7. For liquids, an isentropic process is also an isothermal process. 8. The rate of conduction heat transfer is proportional to the conductivity and materials thickness. 9. The area under the T-S diagram is entropy generation. 10. Hydrogen cars has a higher efficiency compared to electric cars