2. Compare the various states of matter in state ofpotential and kinetic energy
3. Explain the significant events that take place along a heatingcurve.
You are watching: Evaporation of water exothermic or endothermic
4. Translate a phase diagram.
Key Terms:
vaporization condensationevaporation equilibrium vapor pressureboiling suggest heat the vaporization freezingpoint warm of fusionsublimation deposition heatingcurve phase diagram
Notes: (14-4)
Matter on Earthexists together either liquid, solid, or gas. Other than water, many matterexists in a solitary phase (liquid, solid, or gas) yet can it is in made to adjust phaseby including or deleting press or temperature.
Energy and also PhaseChanges
According to thekinetic-molecular theory, a substances phase is established by the balance the itskinetic and intermolecular forces. What this way is the you can convertmatter indigenous one phase to an additional by simply adding or deleting kinetic energy(heat). As soon as attempting to know the phase changes it is essential toremember what is developing in endo and also exothermic reactions.

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Changesin State:
liquid come gas - vaporization, by process of evaporation | |
solid to gas - sublimation | |
liquid come solid - freezing | |
gas to fluid - condensation | |
gas come solid - deposition |
Evaporation
Evaporation is again explained by theKinetic-molecular theory. When the kinetic power of the molecule in aliquid come to be greater than the intermolecular attractions in between them,evaporation occurs.
within a liquid, evaporation is always occurring to some level at the surface of the liquid | |
Temperature and also evaporation price are directly related | |
Liquids with high evaporation rates are claimed to be volatile - commonly flammable because of the presence of necessary materials and oxides | |
Evaporation cools a surface or equipment by remove the molecules through the greatest kinetic energy | |
Most remedies in a close up door container room in liquid-vapor equilibrium | |
condensation and evaporation rates are equal | |
rate of molecule leaving the solution space equal come the molecule entering the liquid | |
The systems is at equilibrium vapor pressure |
Boiling Point:
The boiling allude of a liquid is straight relatedto the vapor press of the liquid. Vapor pressure is a measure up of thevapor existing in a liquid. As soon as the vapor pressure equals the atmosphericpressure boil occurs. That is essential to remember the vaporization i am one endothermic process as warmth is eliminated from the liquid with boiling.
vapor push of a liquid is straight related come the temperature used to the liquid | |
the boiling suggest is straight related to the atmospheric push exerted ~ above the solution | |
boiling occurs as soon as the vapor press = atmospheric pressure | |
the temperature of a liquid will certainly remain consistent at the boiling suggest until all of the liquid is vaporized. |
Freezing and also Melting:
The freezing and melting clues of a liquid existat the same temperature and represent one equilibrium in between the fluid andsolid phases.
melting and also freezing points room not greatly impacted by atmospheric pressure | |
melting depends on the warmth of blend which favor the boil is an endothermic process | |
freezing supplies the exact same amount of power as the warm of fushion bu is one exothermic process |
Heating Curves:

((server.chem.ufl.edu/~itl/2045_s99/ lectures/FG11_024.GIF))
The heating curve is a depiction of thephases the a substance compared to the temperature and also internal power of asubstance. The blue lines stand for the various phases the a substancewhile the red lines stand for the heats of combination and vaporization.
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endothermic reactions relocate from left to right as the commodities increase in kinetic energy and also become much less organized |
Phase Diagrams

((server.chem.ufl.edu/~itl/2045_s99/ lectures/FG11_024.GIF))
The step diagram is one more representation ofthe internal energy of a substance contrasted with the pressure and also temperature ofits surroundings.
temperature and also pressure room inversely pertained to the procedure of vaporization | |
pressure has little effect top top the melting and also freezing of a substance | |
the triple suggest is a suggest where all 3 phases take place in equilibrium |
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