2. To compare the various states of matter in terms ofpotential and kinetic energy

3. Describe the significant events that happen along a heatingcurve.

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

4. Analyze a phase diagram.

Key Terms:

vaporization condensationevaporation equilibrium vapor pressureboiling suggest heat the vaporization freezingpoint heat of fusionsublimation deposition heatingcurve phase diagram

Notes: (14-4)

Matter top top Earthexists as either liquid, solid, or gas. Other than water, many matterexists in a single phase (liquid, solid, or gas) but can be made to adjust phaseby including or deleting push or temperature.

Energy and also PhaseChanges

According to thekinetic-molecular theory, a substances phase is established by the balance the itskinetic and also intermolecular forces. What this means is the you deserve to convertmatter from one step to another by simply adding or deleting kinetic energy(heat). When attempting to recognize the phase alters it is important toremember what is developing in endo and exothermic reactions. Endothermic - power is being absorbed - bonds space breaking - products are much less ordered Exothermic - power is gift released - bonds space being created - products are more ordered


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

Changesin State:

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


Evaporation is again described by theKinetic-molecular theory. Once the kinetic energy of the molecules in aliquid end up being greater than the intermolecular attractions in between them,evaporation occurs.

within a liquid, evaporation is always occurring come some degree at the surface of the liquid
Temperature and evaporation price are straight related
Liquids with high evaporation prices are claimed to it is in volatile - typically flammable as result of the visibility of essential materials and oxides
Evaporation cools a surface ar or systems by removed the molecules through the highest possible kinetic energy
Most services in a closed container space in liquid-vapor equilibrium
condensation and also evaporation prices are equal
price of molecules leaving the solution are equal to the molecule entering the liquid
The equipment is at equilibrium vapor pressure

Boiling Point:

The boiling suggest of a liquid is directly relatedto the vapor push of the liquid. Vapor push is a measure up of thevapor present in a liquid. Once the vapor pressure equates to the atmosphericpressure cook occurs. It is essential to remember the vaporization isan endothermic procedure as heat is gotten rid of from the liquid v boiling.

vapor press of a fluid is directly related come the temperature applied to the liquid
the boiling allude is straight related to the atmospheric press exerted ~ above the solution
boiling occurs when the vapor push = atmospheric pressure
the temperature the a liquid will remain consistent at the boiling suggest until every one of the liquid is vaporized.

Freezing and Melting:

The freezing and also melting point out of a fluid existat the very same temperature and also represent an equilibrium between the fluid andsolid phases.

melting and freezing points space not greatly influenced by atmospheric pressure
melting depends on the warmth of blend which like the boiling is one endothermic process
freezing provides the 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 heater curve is a depiction of thephases the a substance compared to the temperature and internal energy of asubstance. The blue lines represent the different phases that a substancewhile the red lines stand for the heats of fusion and vaporization.

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

endothermic reactions move from left to appropriate as the commodities increase in kinetic energy and become less organized

Phase Diagrams


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

The phase diagram is another representation ofthe internal power of a substance contrasted with the pressure and also temperature ofits surroundings.

temperature and pressure room inversely concerned the process of vaporization
pressure has small effect top top the melting and also freezing that a substance
the triple allude is a allude where all 3 phases occur in equilibrium