Chapter 10, Problem 17A

Interpretation Introduction

Interpretation: In thermodynamics, the system’s point of view taken by chemist needs to be explained.

Concept Introduction: In an exothermic reaction energy discharges from the system while in endothermic reaction energy consumed from the surrounding. The internal energy E of a system is altered by a work flow, heat or both.

Answer to Problem 17A

The chemist chooses for the energy-based sign that passes into or out of the system.

Explanation of Solution

If the energy is denoted by positive sign then the process is endothermic that means the process absorbs energy from the surrounding. And if energy is denoted by negative sign, the process is exothermic that means the process discharge energy from the system.

If work has a negative sign it indicates the system is doing work on its surroundings. If work is reported by positive symbol then the surrounding is doing work on the system.

Conclusion

In endothermic process, system’s energy increases while in exothermic process, system’s energy decreases.