ΔU = Q - W
Where ΔU is the change in internal energy, Q is the heat added to the system, and W is the work done by the system.
Example: A heat engine adds 100J of heat to a system, but the system does 50J of work. What is the change in internal energy?
ΔU = 100 - 50 = 50J
More examplespV = nRT
Where p is the pressure, V is the volume, n is the number of moles, and R is the gas constant.
Example: A gas has a pressure of 2 atm, a volume of 10L, and 2 moles. What is the temperature?
R = 0.08206 L atm / (mol K)
T = pV / nR = (2 atm)(10L) / (2 mol) / (0.08206 L atm / mol K) = 122.06K
More examples