aspargine
IiTeachChem
•Created by minttea on 1/19/2025 in #💭│doubts
WHY is first law of thermodynamics different in physics and chemistry
interesting one !!
the definition of 'W' in both the subjects is different (Note that, definition of work done is universal; provided the displacement and force is specified).
In Chemistry, we define 'W' as work done by the surroundings(piston) on the system (gas). so whenever gas expands, it does displacement against the force applied by the piston, which results in negative value of 'W'.
whereas,,
In Physics, we define 'W' as work done by the system (gas) on the surroundings (piston). Here say, if the gas is expanding, the displacement of the piston is in the direction of the force applied on it by the gas. so, according to the definition of 'W', its positive.
In short, the symbol 'W' has different meanings in physics and Chemistry. Its up to us, whether we are considering the force applied is by the gas or by the piston.
Conventionally, if we write 'W' in chemistry, it means work done by the piston on the system.
Technically we should specify it, inspite of writing just 'W'.
hope it helpss !!
169 replies
IiTeachChem
•Created by Manticore on 12/24/2024 in #💭│doubts
Jee mains 2024 solutions
there are subject wise ig
11 replies