Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
31 Cards in this Set
- Front
- Back
|
Heat
|
A form of energy that can be transferred between substances in thermal contact when there is a temperature difference.
|
|
|
SI unit of Heat
|
Joules (J)
|
|
|
Common (non-SI) unit of Heat
|
Kilocalories (kcal)
|
|
|
Relationship between kcals and joules
|
1 kcal = 4186 J
|
|
|
Mechanical equivalent of heat
|
The name for the ratio between calories a joules:
1 cal = 4.186 J |
|
|
Specific Heat
|
The amount of heat required to change the temperature of 1 kg of a substance by 1 degree C.
|
|
|
SI notation for specific heat
|
c = J/kg*K = J/kg*C
|
|
|
Specific heat of water?
|
4186J / kg*C OR 1.00 kcal/kg*C
|
|
|
Calorimetry
|
The quantitative measure of heat exchange that allows determining specific heats of substances. During this process we must assume that no heat is lost to the surroundings.
|
|
|
What are the two specific heats of gases?
|
Specific heat at constant pressure (Cp) and specific heat at constant volume (Cv)
|
|
|
What is the equation for the specific heat of a gas at constant pressure (Cp)?
|
Cp = (Q/nΔT)
|
|
|
What is the equation for the specific heat of a gas at constant volume(Cv)?
|
Cv = (Q/nΔT)
|
|
|
Which must always be larger: the specific heat of a gas at constant volume (Cv), or the specific heat of a gas at constant pressure (Cp)?
|
Cp > Cv
|
|
|
What does the addition of heat do to the molecules of a substance (assuming no phase change occurs)?
|
The heat further increases the motion of the molecules.
|
|
|
What is the name for the temperature at which gases condense?
|
Condensation point
|
|
|
Sublimation
|
Changing directly from solid to gaseous phase.
|
|
|
Deposition
|
Changing directly from gaseous to solid phase.
|
|
|
Latent Heat
|
The magnitude of heat (Q) needed for phase change per unit mass:
L = |Q| / m |
|
|
SI units for Latent Heat
|
J / kg
|
|
|
Latent heat of fusion
|
The latent Heat needed to melt a substance.
|
|
|
Latent heat of Vaporization
|
The latent heat needed to convert a liquid to a gas.
|
|
|
Latent heat of Sublimation
|
The latent heat needed to convert a solid directly to a gas.
|
|
|
What is the change in temperature of a substance during a phase change?
|
Temperature does not change during a phase change.
|
|
|
Latent heat of Fusion for water
|
3.33 x 10^5 J/kg
|
|
|
Latent heat of Vaporization for water
|
22.6 x 10^5 J / kg
|
|
|
As pressure decreases, the boiling point of a substances does what?
|
It decreases.
|
|
|
As pressure increases, the melting point of a substance does what?
|
It decreases.
|
|
|
Three methods of heat transfer
|
Conduction, Convection, Radiation
|
|
|
Conduction
|
The process by which heat flows through a material without any bulk motion. Energy is transferred by means of molecular collisions.
|
|
|
Thermal Conductors
|
Materials (such as metals) that conduct heat well.
|
|
|
Thermal Insulators
|
Materials that do not conduct heat well (gases).
|
