Question

Which of the following is a restatement of first law of thermodynamics:

• A. Guy-Lassac's Law
• B. The principle of entropy
• C. The principle of enthalpy
• D. Conservation of energy
• E. Avogadro's hypothesis

Answer 1

Answer: (D)

Conservation of energy

First law of thermodynamics states that the quantity of heat given to a system $dQ$ is equal to the sum of the increase in its internal energy $dU$ and the external work done by the system $dW$ in expansion

$dQ=dU+dW$

it means total energy is conserved there is no loss of energy