Question

The first law of thermodynamics is concerned with conservation of:

• A. number of molecules
• B. number of moles
• C. energy
• D. temperature

Answer 1

Answer: (C)

The first law of thermodynamics gives $Q=\Delta U+W$ which states that if an amount of heat $Q$ is given to a system a part of it will be used in increasing the internal energy $(\Delta U)$ of the system and the rest in doing work $(W)$ by the system. Thus, the first law of thermodynamics is a form of law of conservation of energy.