Heat of 30 kcal is supplied to a system and 4200 J of external work is done on the system so that its volume decreases at constant pressure. What is the change in its internal energy ? (J=4200 J/kcal)
There is no answer for my qn
To find the change in the internal energy of the system, we need to consider the heat supplied to the system and the external work done on the system.
The heat supplied to the system is given as 30 kcal. We can convert this into joules by using the conversion factor 1 kcal = 4200 J. Therefore, the heat supplied in joules is:
30 kcal * 4200 J/kcal = 126000 J
The external work done on the system is given as 4200 J.
To find the change in internal energy, we can use the First Law of Thermodynamics, which states that the change in internal energy (ΔU) is equal to the heat supplied to the system minus the work done by the system:
ΔU = Q - W
Substituting the values we have:
ΔU = 126000 J - 4200 J
= 121800 J
Therefore, the change in the system's internal energy is 121800 J.