106They dont differ
Consider the sign conventions...
They two come out to be the same
Its just that in Phy we take Work done by gas as +ve and in Chem work done by gas is -ve
So, considering the sign scheme both are equivalent
NCERT chemistry:
First law of thermodynamics:
In general:
ΔU=q+w ------------------(1)
ΔU change in internal energy,q-heat transferd,w-work done by or on the system
NCERTphysics:
ΔQ=ΔU+ΔW --------------(2)
ΔQ- heat supplid to the system between two states
ΔU- internal energy change between two states
Δw-work done between two states.
The dbt is why these two eqns differs.
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7 Answers
106
11Ya asish is right..
even i got confused first msp..
just the sign conventions they use is different..otherwise both are the same.
3Yes i know dat asish,but if first law of td is universal and y its not having a same defn,I mean y shud u alter terms and y do apply different convention,There is one more dbt asish see in the second eqn we have terms of "Δ".That is we are speaking abt change between two states,but its not in the first eqn.
3See we have newtons law in which we apply same convention in every texts na.
1357In physics, we use the concept that the work done is positive when displacement is in the direction of force.
In chemistry, we use anything as positive which has ability to increase internal energy
1its a sign coventataion problem , in chemistry work done n=by external agent is opposite to in the physics