Chemical Thermodynamics — Chemistry STD 12 Science — Question

First law of thermodynamics:-
If the quantity of heat supplied to a system is capable of doing work, then the quantity of heat absorbed by the system is equal to the sum of the increase in the internal energy of the system and the external work done by it.
The equation which supports the first law of thermodynamics mathematically is
ΔU = q + w
When expressed in the differential form, the same relationship takes the following form:
dQ = dU + dL