15. Which one of the following statements describes a path function? (A) A property of a system that depends only on the current state of the system, not on the path the system took to reach that state. (B) A property of a system that depends on the path taken between the initial and final states. (C) The sum of kinetic and potential energy contained in a substance. (D) The heat energy absorbed by a system at constant pressure. 16. An isolated system is best described by which one of the following statements? (A) The boundary of a system allows heat transfer but does not allow matter to pass into or out of the system (B) The system has a diathermic boundary (C) Neither matter nor heat can flow into or out of the system (D) A system which has reached thermal equilibrium with its surroundings 17. Which statement is false? (A) No work is done in a reaction occurring in a bomb calorimeter. (B) H is equal to q at constant pressure. (C) H is equal to U for the reaction. (D) Irreversible work is smaller than reversible work