Calculate the external work done by the system in Kcal, when 40kCal of heat is supplied to the system, 8400 J of internal work is done.

Explanation

Heat supplied to the system at constant pressure = change in internal energy + External work done
The change in internal energy = Internal work done= `8400J=8400/4200` KCal = 2 KCal.
`:. 40 KCal = 2 kCal` + External work done
The external work done = `40-2=38 kCal `