Question

How do we define positive and negative of heat and work?

a) Positive when absorbed by the system
b) Positive when released by the system
c) Negative when absorbed by the system
d) Negative when released by the system

Answer 1

By convention, heat flow and work have a negative sign when energy is transferred from a system to its surroundings and vice versa.

Step-by-step explanation:

By convention, heat flow and work are given a negative sign when energy is transferred from a system to its surroundings and vice versa. Therefore, the sign convention for heat is negative when it is released by the system and positive when it is absorbed by the system. Similarly, the sign convention for work is negative when it is done by the system on its surroundings and positive when it is done on the system by its surroundings.