Chemistry Test 2-26-09

kinetic energy
the energy an object has because of its motion
kinetic theory (term)
states that the tiny particles in all forms of matter are in constant motion
gas pressure
the force exerted by a gas per unit surface area of an object
vacuum
an empty space with no particles or pressure
atmospheric pressure
results from the collisions of air molecules with objects
barometers
devices commonly used to measure atmospheric pressure
pascal (Pa)
the SI unit of pressure
standard atmosphere (atm)
the pressure required to support 760mm of mercury in a mercury barometer at 25 C
vaporization
the conversion of a liquid to a gas or vapor
evaporation
vaporization that occurs at the surface of a liquid that is not boiling
vapor pressure
force due to the gas above the liquid
boiling point
the temperature at which the vapor pressure of the liquid is equal to the external pressure
normal boiling point
the boiling point of a liquid at a pressure of 101.3 kPa
phase diagram
gives the conditions of temperature and pressure at which a substance exists as a solid, liquid, and gas
triple point
describes the only set of conditions at which all three phases can exist in equilibrium with one another
sublimation
change of a substance from a solid to a vapor without passing through a liquid state
thermochemistry
concerned with the heat changes that occur during chemical reactions
energy
the capacity for doing work or supplying heat
chemical potential energy
energy stored within the structural units of chemical substances
heat
energy that transfers from one object to another because of a temperature difference between them
system
the part of the universe on which you focus your attention
surroundings
everything else in the universe
universe
the system and its surroundings together
law of conservation of energy
states that in any physical or chemical process, energy is neither created nor destroyed
endothermic process
process that absorbs heat from the surroundings
exothermic process
process that releases heat to its surroundings
calorie
the quantity of heat needed to raise the temperature of 1 g of pure water 1 C
joule
the SI unit of heat and energy
heat capacity
the amount of heat needed to increase the temperature of an object exactly 1 C
specific heat capacity (specific heat)
the amount of heat it takes to raise the temperature of 1g of a substance 1 C
Kinetic Theory (3 parts)
1. No attractive or repulsive forces exist between the particles.
2. The particles of a gas move rapidly in constant random motion (random walk).
3. All collisions are perfectly elastic (total kinetic energy remains constant).
STP
0 C and 101.3 kPa
0C=
273K
state of matter closest to kinetic theory
gases
C=
J/(g x deltat)
water specific heat
4.18 J