Physics Quiz 7(Thermodynamics) Flashcards
What is latent heat?
When a substance changes from one state to anther, latent heat is added or released in the process.
For example:
Ice—>Vapor(latent heat of sublimation is added)
Vapor—->Ice(latent heat of deposition is released)
The amount of heat required to change 1 gram of ice at 0’C to 1 gram of water at 0’C is 80 calories. What is this called?
Heat of fusion of water
To change 1 gram of water at 100’C to water vapor at 100’C requires 540 calories of heat. What is this called?
Heat of vaporization
What is the process called by which water changes to its gaseous state(water vapor)?
Boiling or evaporating
How many calories of heat is added for ice to melt to water?
80
How many calories of heat are added for ice to evaporate from water to vapor?
540
In the warming process between 0’C and 100’C how many calories are added?
100
How many calories of heat are removed for water vapor to cool to the liquid form of water?
540
How many calories of heat are removed as water cools from 100’C to 0’C?
100
How many calories of heat are removed for water to freeze to a solid form of ice?
80
What is Sublimation, and what is an example of it?
Sublimation is the change of a solid substance directly to a vapor without first passing through the liquid state. Two examples of this is iodine and Dry Ice(solid carbon dioxide which sublimes at -78.5’C)
What is Deposition and what is an example of it?
Deposition is a process where a gas changes phase and turns directly into a solid without first passing through the liquid phase. One common example is snow that is formed in the clouds. Water vapor changes directly to ice without first becoming liquid.
What is the opposite of Sublimation?
Deposition
For molecules in water, what does average kinetic energy depend upon?
temperature
What describes the attractive and repulsive forces between water molecules that make their motion quite random?
This is known as Brownian motion
As greater kinetic energy(higher temperatures) is applied to water molecules what happens?
They move apart ultimately the greater kinetic energy allows them to escape individually as a vapor.
As smaller kinetic energy(lower temperatures) is applied to water molecules what happens?
They move closer together becoming a solid(ice).
What is the difference between heat versus temperature?
Temperatures can be viewed as an arbitrary numerical ranking of “hotness” or “coldness”.
Heat can be viewed as energy that is transferred as a result of a temperature difference(it is an energy flow).
When two bodies of unequal temperatures are brought into contact, a flow of heat occurs from the hot object to the cold object until the two temperatures become equal.
What is the quantitative measurement of of thermal energy?
temperature
What is referred to as thermal energy?
heat
What is the equation converting Celsius to Kelvin?
K=’C + 273
What is the equation converting Celsius to degree Fahrenheit?
‘F=1.8(C’)+32
What is the equation converting Fahrenheit to degree Celsius?
‘C=(‘F-32)/1.8
What is the numerical representation of standard temperature?
273K or 0’C
What is another word to describe heat?
energy
Heat loss(energy loss) is unidirectional from what to what?
higher concentration to a lower concentration. Hotter to less hot.
The human body is a system that contains energy and there is a constant exchange of heat with the environment from high concentration to lower concentration.
What is a word used to describe the protective mechanisms such as vasoconstriction of peripheral vessels that slows heat loss from our bodes and vasodilation of peripheral vessels that promotes heats loss when we are exposed to a warmer environment?
Thermoregulation
A patient’s core temp can quickly drop by the vasodilating actions of anesthetics, when is the greatest decrease seen?
the greatest decrease is in the first hour