Why is heat of vaporization, heat of fusion, and heat of sublimation accounted as energy generation in the usual derivation of energy balance equations?
What will be an ideal response?
Heats of vaporization, fusion, and sublimation are energy measures accounting
for phase changes and not directly to temperature or pressure changes. It is
convenient, therefore, to account these phase change energies as lumped
terms, or energy generation.
You might also like to view...
The diagram above shows the life track of a 1 MSun protostar from the time it first begins to form until it reaches the main sequence, with four stages labeled. What is happening to the protostar's surface temperature and luminosity during Stage 1, when gravity assembles the protostar from a collapsing cloud?
A) Its surface temperature and luminosity increase. B) Its surface temperature remains the same and its luminosity decreases. C) Its surface temperature and luminosity decrease. D) Its surface temperature decreases and its luminosity increases. E) Its surface temperature and luminosity remain the same.
What happened during the accretion phase of the early solar system?
A) Atoms and molecules in the gas bonded together and solidified. B) Particles grew by colliding and sticking together. C) The solar nebula differentiated into metals inside of the frost line and ices beyond. D) Large planetesimals captured atmospheres from the solar nebula. E) Earth gained its oceans from icy planetesimal capture.
Jet planes operate by
A) rocket drive [i.e., ejecting heated rocket fuel rapidly out the back end of the engine]. B) ejecting ions out the back end of the engine. C) sucking in air, heating it , and allowing it to expand out the back end of the engine. D) sucking in air and blowing it rapidly out the back of the engine by means of propeller blades inside the engine. E) magic.
The hydrogen spectrum has a red line at 656 nm, and a blue line at 434 nm. What is the first order angular separation between the two spectral lines obtained with a diffraction grating with 5000 rulings/cm?
a. 7.7° b. 16.6° c. 6.6° d. 3.2° e. 19.2°