D)2.1 Work, heat, and energy Exothermic process: one that releases energy as heat. Endothermic process: one that absorbs energy as heat (a)When an endothermic process occurs in an adiabatic system, the temperature falls; (b)if the process is exothermic, then the temperature rises.(c) when an endo- (a) thermic process occurs in a diathermic container, energy enters as heat from the Isothermal surroundings, and the system remains at the same temperature; (d) if the process is Heat Heat exothermic, then energy leaves as heat, and the process is isothermal 版权所有:华东理工大学物理化学教研室
版权所有：华东理工大学物理化学教研室 6 Exothermic process: one that releases energy as heat. Endothermic process: one that absorbs energy as heat. (a) When an endothermic process occurs in an adiabatic system, the temperature falls;(b) if the process is exothermic, then the temperature rises. (c) When an endothermic process occurs in a diathermic container, energy enters as heat from the surroundings, and the system remains at the same temperature;(d) if the process is exothermic, then energy leaves as heat, and the process is isothermal. 2.1 Work, heat, and energy
D)2.1 Work, heat, and energy Heat-molecular interpretation Surroundings Heat is the transfer of energy that makes use of chaotic molecular motion The chaotic motion of molecules is called thermal motion. When a system heats its surroundings, molecules Energy Energy of the system stimulate the thermal motion of the molecules System in the surroundings 版权所有:华东理工大学物理化学教研室
版权所有：华东理工大学物理化学教研室 7 Heat-molecular interpretation Heat is the transfer of energy that ma kes u se of chaotic molecular motion. The chaotic motion of molecules is called thermal motion. When a system heats its surroundings, molecules of the system stimulate the thermal motion of the molecules in the surroundings. 2.1 Work, heat, and energy
D)2.1 Work, heat, and energy Work-molecular interpretation Surroundings Work is the le transfer of energy that makes use of organized motion. When a system does work, it stimulates orderly Energy Energy motion in the surroundings 版权所有:华东理工大学物理化学教研室
版权所有：华东理工大学物理化学教研室 8 Work-molecular interpretation Work is the transfer of energy that makes use of organized motion. When a system does work, it stimulates orderly motion in the surroundings 2.1 Work, heat, and energy
The basic concepts 2.1 Work, heat, and energy 2.2 The first law 1). The internal energy 2). The conservation of energy 3). The formal statement of the First Law 版权所有:华东理工大学物理化学教研室
版权所有：华东理工大学物理化学教研室 9 The basic concepts 2.1 Work, heat, and energy 2.2 The First Law 1). The internal energy 2). The conservation of energy 3). The formal statement of the First Law
2.2 The first law 1). The internal energy The internal energy, U: the total energy of a system is called its internal energy; it is the total kinetic and potential energy of the molecules composing the system The internal energy is a state function. It is a extensive property. Internal energy, heat, and work are measured in the same units, the Joule(j). 版权所有:华东理工大学物理化学教研室
版权所有：华东理工大学物理化学教研室 10 The internal energy, U : the total energy of a system is called its internal energy;it is the total kinetic and potential energy of the molecules composing the system. The internal energy is a state function. It is a extensive property. Internal energy, heat, and work are measured in the same units, the Joule (J). 2.2 The First Law 1). The internal energy