OnlineCBT
Chemistry · THERMODYNAMICS
हिन्दीWhy is the absolute value of internal energy (\( U \)) of a system impossible to determine, whereas the change in internal energy (\( \Delta U \)) is readily measurable?
Correct answer · Option 3
Because internal energy includes translational, rotational, vibrational, electronic, and nuclear energies, whose absolute sum cannot be evaluated, but changes during physical/chemical processes can be quantified via heat and work.
Explanation
Internal energy represents the sum of all microscopic forms of energy (chemical, electrical, mechanical, molecular) which cannot be known absolutely; however, \( \Delta U = q + w \) can be precisely measured experimentally.
