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Sublimation is the transition from solid to vapor phase. You may have noticed that snow can disappear into thin air without a trace of liquid water, or the disappearance of ice cubes in a freezer. The reverse is also true: Frost can form on very cold windows without going through the liquid stage. A popular effect is the making of “smoke” from dry ice, which is solid carbon dioxide. Sublimation occurs because the equilibrium vapor pressure of solids is not zero. Certain air fresheners use the sublimation of a solid to inject a perfume into the room. Moth balls are a slightly toxic example of a phenol (an organic compound) that sublimates, while some solids, such as osmium tetroxide, are so toxic that they must be kept in sealed containers to prevent human exposure to their sublimation-produced vapors.

Figure a shows vapors flowing out from the middle of three glasses placed adjacently on a table. This glass contains a piece of dry ice in lemonade. Two squeezed lemon slices are also seen alongside the glasses. Figure b shows frost patterns formed on a window pane.
Direct transitions between solid and vapor are common, sometimes useful, and even beautiful. (a) Dry ice sublimates directly to carbon dioxide gas. The visible vapor is made of water droplets. (credit: Windell Oskay) (b) Frost forms patterns on a very cold window, an example of a solid formed directly from a vapor. (credit: Liz West)

All phase transitions involve heat. In the case of direct solid-vapor transitions, the energy required is given by the equation Q = mL s size 12{Q= ital "mL" rSub { size 8{s} } } {} , where L s size 12{L rSub { size 8{s} } } {} is the heat of sublimation    , which is the energy required to change 1.00 kg of a substance from the solid phase to the vapor phase. L s size 12{L rSub { size 8{s} } } {} is analogous to L f size 12{L rSub { size 8{f} } } {} and L v size 12{L rSub { size 8{v} } } {} , and its value depends on the substance. Sublimation requires energy input, so that dry ice is an effective coolant, whereas the reverse process (i.e., frosting) releases energy. The amount of energy required for sublimation is of the same order of magnitude as that for other phase transitions.

The material presented in this section and the preceding section allows us to calculate any number of effects related to temperature and phase change. In each case, it is necessary to identify which temperature and phase changes are taking place and then to apply the appropriate equation. Keep in mind that heat transfer and work can cause both temperature and phase changes.

Problem-solving strategies for the effects of heat transfer

  1. Examine the situation to determine that there is a change in the temperature or phase. Is there heat transfer into or out of the system? When the presence or absence of a phase change is not obvious, you may wish to first solve the problem as if there were no phase changes, and examine the temperature change obtained. If it is sufficient to take you past a boiling or melting point, you should then go back and do the problem in steps—temperature change, phase change, subsequent temperature change, and so on.
  2. Identify and list all objects that change temperature and phase.
  3. Identify exactly what needs to be determined in the problem (identify the unknowns). A written list is useful.
  4. Make a list of what is given or what can be inferred from the problem as stated (identify the knowns).
  5. Solve the appropriate equation for the quantity to be determined (the unknown). If there is a temperature change, the transferred heat depends on the specific heat (see [link] ) whereas, for a phase change, the transferred heat depends on the latent heat. See [link] .
  6. Substitute the knowns along with their units into the appropriate equation and obtain numerical solutions complete with units. You will need to do this in steps if there is more than one stage to the process (such as a temperature change followed by a phase change).
  7. Check the answer to see if it is reasonable: Does it make sense? As an example, be certain that the temperature change does not also cause a phase change that you have not taken into account.

Questions & Answers

What's the difference between deceleration and negative acceleration?
Lee Reply
Busola Reply
are you asking for the mnemonics or you want to share it with us.?!?
While operating, a TV monitor is placed on its side during maintenance. The image on the monitor changes color and blurs slightly. Discuss the possible relation of these effects to the Earth’s magnetic field.
Dedachew Reply
WhileGot questions? Get instant answers now! operating, a TV monitor is placed on its side during maintenance. The image on the monitor changes color and blurs slightly. Discuss the possible relation of these effects to the Earth’s magnetic field.
what is physic
Haagensen Reply
what is a fundamental unit
Sakish Reply
what is fundamental unit
Sakish Reply
fundamental unit is a unit adopted for measurement of a base quantity. A base quantity is one of a conventionally chosen subset of physical quantities, where no subset quantity can be expressed in terms of the others. Length (meter) Mass (kilogram) Time (second) Electric current (ampere) Thermodynam
explain the term doping as used in electronics
I do not understand maybe u can help me explain it
what are kinetics
Vincent Reply
what is longitudinal wave
Wave consisting of a periodic disturbance or vibration that takes place in the same direction as the advance of the wave
please can you help me define periodic disturbance
list five fundamental unit
Sunday Reply
can someone make me understand how to solve ohms? please
fortune Reply
please can someone teacher me how to plot physics graphs
wat topic is ohms
ohms is the unit for resistance, so you must mean electricity
@Fortune Emmanuel ☆ Consider the axes ☆ In physics (Displacement time graph, Velocity time graph, Gravitational acceleration time graph)are the basic graphs. ☆Correctly plot the points and lines according to the correct acceleration, deceleration, uniform motion, velocity given in the question.
A man cycle up a hill whose slop is 1 in 20. if the masses of the man and bicycle is 150kg and the masses covers a distance of 100m along the inclined, calculate the work done by the man.
Makumbi Reply
what's the Answer?
what is angular momentum?
Tandeka Reply
It is the property of a rotating body given by the product of the moment of inertia and the angular velocity of the rotating object
state Newton first law
HOM Reply
it states that an object will continue in a constant motion unless altered by an external force.
Newton's first law of motion state that an object continue in it's state of rest or of uniform motion unless acted upon by an external force to act otherwise known as inertia
it states that an object will remain in rest or constant motion until an external force is applied to it
please what is Newton's second law of motion
why is it that tall building are mounted with lightning conductors
Shedrack Reply
why it is that tall buildings are mounted with lightning conductors
taller structures have a high risk of being struck by lightning
so that lightening can't stock the pipo in it,it reacts like a conductor of electricity
a 50kg mass is placed on a frictionless piston fitted to a gas cylinder .If 149 kelvin of heat is supplied to the cylinder increasing the internal energy by 100 joules,determine the height through which the mass of the piston raise
Lawal Reply
what is thermodynamics
wana Reply
thermodynamic is a branch of physics that teaches on the relationship about heat and anyother form of energy
could you please help solve question on thermodynamics
if a mass of 149 of heat is supplied and there's an increase in internal energy of 100jouls,find the raise in height
Practice Key Terms 3

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Source:  OpenStax, College physics. OpenStax CNX. Jul 27, 2015 Download for free at http://legacy.cnx.org/content/col11406/1.9
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