THERMODYNAMICS [CHEM. vs PHYSICS]

     The biggest confusion that some students face in thermodynamics is different sign conventions of "work" in chemistry and physics... i have gone through the same situation...
let me clear this confusion..

     In chemistry and physics sign conventions of work are opposite because of which it seems that equation of first law of thermodynamics is different for chemistry and physics.

 The equation is.. 
                   PHYSICS             -    dQ=dE+W
                 CHEMISTRY        -    dE=dQ+W
where "Q"is heat,"E" is internal energy and "W" is work done.

                                          WORK
    EXPANSION-        work done by the system
    COMPRESSION-   work done on the system

                               SIGN CONVENTION

                                         PHYSICS

•    Expansion                 -                     positive 
•    Compression             -                     negative

                                     CHEMISTRY

• Expansion                    -                   negative
• Compression                -                   positive

     So,in actual the first law of thermodynamics is not different for both the subjects but the sign conventions of work  makes the difference.