2. Compare the various says of issue in terms ofpotential and kinetic energy

3. Describe the significant events that take place alengthy a heatingcurve.

You are watching: Is the evaporation of water endothermic or exothermic

4. Interpret a phase diagram.

Key Terms:

vaporization condensationevaporation equilibrium vapor pressureboiling point heat of vaporization freezingpoint warm of fusionsublimation deposition heatingcurve phase diagram

Notes: (14-4)

Matter on Earthexists as either liquid, solid, or gas. Other than water, many matterexists in a solitary phase (liquid, solid, or gas) however have the right to be made to readjust phaseby including or deleting push or temperature.

Energy and PhaseChanges

According to thekinetic-molecular theory, a substances phase is figured out by the balance of itskinetic and intermolecular forces. What this implies is that you can convertmatter from one phase to one more by simply including or deleting kinetic energy(heat). When attempting to understand also the phase transforms it is essential toremember what is emerging in enperform and exothermic reactions. Endothermic - Energy is being soaked up - bonds are breaking - products are less ordered Exothermic - Energy is being released - bonds are being developed - assets are even more ordered


(server.chem.ufl.edu/~itl/2045_s99/ lectures/FG11_024.GIF)

Changesin State:

liquid to gas - vaporization, by process of evaporation
solid to gas - sublimation
liquid to solid - freezing
gas to liquid - condensation
gregarding solid - deposition


Evaporation is again explained by theKinetic-molecular concept. When the kinetic power of the molecules in aliquid become greater than the intermolecular attractions in between them,evaporation occurs.

within a liquid, evaporation is constantly developing to some degree at the surchallenge of the liquid
Temperature and also evaporation rate are directly related
Liquids through high evaporation prices are sassist to be volatile - commonly flammable because of the presence of organic materials and oxides
Evaporation cools a surchallenge or solution by removing the molecules via the highest possible kinetic energy
Many options in a closed container are in liquid-vapor equilibrium
condensation and also evaporation rates are equal
rate of molecules leaving the solution are equal to the molecules entering the liquid
The solution is at equilibrium vapor pressure

Boiling Point:

The boiling point of a liquid is directly relatedto the vapor press of the liquid. Vapor pressure is a meacertain of thevapor current in a liquid. When the vapor press equals the atmosphericpush boiling occurs. It is necessary to remember that vaporization isan endothermic process as warmth is rerelocated from the liquid with boiling.

vapor pressure of a liquid is straight related to the temperature applied to the liquid
the boiling allude is straight pertained to the atmospheric press exerted on the solution
boiling occurs as soon as the vapor push = atmospheric pressure
the temperature of a liquid will certainly reprimary consistent at the boiling point until every one of the liquid is vaporized.

Freezing and also Melting:

The freezing and also melting points of a liquid existat the same temperature and represent an equilibrium between the liquid andsolid phases.

melting and freezing points are not substantially impacted by atmospheric pressure
melting counts on the warmth of fusion which like the boiling is an endothermic process
freezing offers the exact same amount of energy as the warmth of fushion bu is an exothermic process

Heating Curves:


((server.chem.ufl.edu/~itl/2045_s99/ lectures/FG11_024.GIF))

The heating curve is a representation of thephases of a substance compared to the temperature and internal energy of asubstance. The blue lines reexisting the various phases of a substancewhile the red lines reexisting the heats of fusion and vaporization.

See more: Eli5: Why Is Sparkling Water Bitter, Why Does Carbonated Water Taste So Bitter

endothermic reactions relocate from left to ideal as the products increase in kinetic energy and also become much less organized

Phase Diagrams


((server.chem.ufl.edu/~itl/2045_s99/ lectures/FG11_024.GIF))

The phase diagram is another representation ofthe internal energy of a substance compared with the press and temperature ofits surroundings.

temperature and also push are inversely related to the process of vaporization
press has little result on the melting and also freezing of a substance
the triple allude is a allude wbelow all three phases occur in equilibrium