Chapter 6 Flashcards
What is the internal energy an object has because of the random motions of its individual molecules?
Thermal energy
What are the three factors that affect thermal energy?
Temperature, State, Mass
What is the state in which no thermal energy is transferred between objects because they are at the same temperature?
Thermal equilibrium
What is the transfer of thermal energy from an object of higher temperature to an object of lower temperature?
Heat
What is the amount of heat needed to change its temperature by a certain amount?
Heat Capacity
C=Q/(delta)T
Heat Capacity formula
What is the ratio of an object’s heat capacity to its mass?
Specific heat
What are the two formulas for specific heat?
c=C/m
c=Q/m(delta)T
What insulated container is a device used to measure heat involved in chemical and physical changes?
Calorimeter
What allows bridges to expand in warm weather and contract in cold weather?
Expansion joints
At what temperature does water stop contracting and begin expanding as it continues to cool?
4 Celsius
What bends in a mechanical thermostat due to the change in temperature?
Bimetallic strip
What are the three methods of heat transfer?
Conduction, Convection, Radiation
What method of heat transfer is the process by which heat flows through materials and between objects in direct contact?
Conduction
Who invented the miner’s safety lamp?
Sir Humphry Davy
What is the transfer of heat through moving fluids?
Convection
What are currents within a liquid caused by heated fluid rising and cooler fluid sinking?
Convection currents
What method of heat transfer can transfer heat without matter?
Radiation
What is a container used to store liquefied gases?
Dewar flask
Where is the only place that heat can escape from in a Dewar flask?
The stopper
What branch of physics deals with thermal energy, heat, and their relationships to other forms of energy and energy transfer?
Thermodynamics
What is the matter or portion of the universe being studied?
System
What are the entire universe except the system?
Surroundings
Which scientist experimented with heating water?
James Prescott Joule
What is the relationship between mechanical energy and heat that Joule discovered?
Mechanical Equivalent of Heat
What principle states that the energy gained or lost by a system is equal to the enemy lost or gained by its surroundings?
First Law of Thermodynamics
What law is the first law of thermodynamics a practical restatement of?
Law of conservation of energy
What is a theoretical device that would generate the maximum possible amount of work from a given amount of heat?
Carnot engine
What states that natural processes only go one way, toward less usable energy and greater disorder?
Second Law of Thermodynamics
What is the measure of the amount of disorder in a system?
Entropy
What is an impossible machine that would generate its own energy once set into motion?
Perpetual motion machine
What is the changing of a solid into liquid?
Melting (or fusion)
What is the changing of a liquid into a solid?
Freezing
Are the melting point and freezing points usually the same temperature?
Yes
What is the phenomenon that occurs when the freezing point of a liquid is lowered by the addition of solutes?
Freezing point depression
What are substances that dissolve in a liquid and affect the freezing point of that liquid?
Solutes
What is the “hidden” heat absorbed or released when a substance undergoes a change of state?
Latent heat
What is the latent heat required to change a given mass of a solid into a liquid without changing its temperature?
Heat of fusion
In order to freeze, a substance must lose latent heat equal to what quantity?
The Heat of Fusion
What is the changing of a substance from liquid to gas?
Evaporation (or vaporization)
What are five factors that determine the rate of evaporation?
- Temperature
- Surface area of the liquid
- Strength of air currents above the liquid
- Air pressure above the surface of the liquid
- Properties of the liquid
What are liquids that evaporate rapidly?
Volatile liquids
What are liquids that evaporate slowly?
Nonvolatile liquids
What is the condition in which evaporation has begun occurring throughout the liquid?
Boiling
How can the boiling point of liquid be controlled?
By controlling the pressure upon the liquid
What is the phenomenon when nonvolatile solutes raise the boiling temperature?
Boiling point elevation
What is the quantity of heat required to change a given amount of liquid already at its boiling point into a gas without raising its temperature?
Heat of vaporization
Which is greater: heat of vaporization or heat of fusion?
Heat of vaporization
What is the changing of a substance from gas into a liquid?
Condensation
What is the pressure that must be exerted by the vapor the the vapor and liquid to be in equilibrium?
Vapor pressure
What is the temperature at which the vapor pressure equals the pressure of the air above the liquid?
Boiling point
What is the temperature above which a substance cannot exist in the liquid state but behaves as a gas regardless of the pressure upon it?
Critical temperature
What are devices that use mechanical energy and latent heat to transfer thermal energy from a colder location to a warmer location?
Heat pumps
What fluid used to transfer thermal energy throughout the system is the most important component of a heat pump?
Refrigerant
What is the radiator that the pressurized refrigerant passes through to cool as it releases heat to the surroundings?
Condenser
What is the winding tube that the warm, highly-pressurized, liquefied refrigerant flows through to be cooled?
Evaporater
What is the changing of a substance from solid to gas, skipping the liquid stage?
Sublimation
What is the changing of a gas directly to a solid, skipping the liquid stage?
Deposition
What is the special state of matter that exists when temperatures are too high for matter to exist in its ordinary states?
Plasma
