 | Term | Definition |
| |
shape |
depdsn on the physical state of matter |
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compressibility |
change in volume of a sample resulting from a pressure change acting on the sample |
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thermal expansion |
change in volume of a sample resulting from a change in temperature of the sample |
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kinetic energy |
energy a particle has as a result of its motion. KE=.5mv^2 |
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potential energy |
energy a particle has as a result of attractive or repulsive forces acting on it |
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cohesive energy |
attractive force between particles |
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disruptive energy |
force resulting from particle motion |
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gas law |
mathematical relationship that describes the behavior of gases as they are mixed, subjected to pressure or temperature changes or allowed to diffuse |
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pressure |
force per unit area of surface on which the force acts. in measurements and calculations involving gases, it is often expressed in units related to measurements of atmospheric pressure |
| |
standard atmosphere |
pressure needed to support a 760mm column of mercury in a barometer tube |
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torr |
pressure needed to support a 1mm column of mercury in a barometer tube |
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absolute zero |
temperature where all the motion stops; a value of 0 on the kelvin scale |
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Boyle's Law |
gas law that describes the pressure and volume behavior of a gas sample kept at constant temperature PV=k |
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Charles's Law |
gas law that describes the temperature and volume behavior of a gas sample kept at constant pressure V/T=k" |
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combined gas law |
gas law that describes the pressure, volume, and temperature behavior of a gas sample PV/T=k" |
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Avogadro's Law |
equal volumes of gases measured at the same temperature and pressure contain equal numbers of molecules |
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standard conditions (STP) |
set of specific temperature and pressure values used for gas measurements |
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ideal gas law |
gas law that related pressure, volume, temperature and number of moles in a gas sample PV=nRT |
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universal gas constant |
constant that relates pressure, volume, temperature and number of moles of gas in an ideal gas law |
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Dalton's law of partial pressures |
total pressure exerted by a mixture of gases is equal to the sum of the partial pressures of the gases in a mixture |
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partial pressure |
pressure an individual gas of a mixture would exert if it were in teh container alone at the same temperature as the mixture |
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effusion |
process where gas escapes from a container through a small hole |
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diffusion |
process that causes gases to spontaneously intermingle when they are brought together |
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Graham's Law |
mathematical expression that relates rates of effusion or diffusion of two gases to the masses of the molecules of the two gases |
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evaporation or vaporization |
endothermic process where a liquid is changed to a gas |
| |
condensation |
exothermic process where a gas or vapor is changed to a liquid or a solid |
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vapor pressure |
pressure exerted by vapor that is in equilibrium with its liquid |
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boiling point |
temperature where the vapor pressure of a liquid is equal to the prevailing atmospheric pressure |
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normal or standard boiling point |
temperature where the vapor pressure of a liquid is equal to 1 standard atmosphere (760 torr) |
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sublimination |
endothermic process where a solid is changed directly to a gas without first becoming a liquid |
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melting point |
temperature where a solid changes to a liquid (solid and liquid have same vapor pressure) |
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decomposition |
change in chemical composition that can result from heating |
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specific heat |
amount of heat energy required to raise the temperature of exactly 1g of a substance by exactly 1 degree Celcius |
| |
heat of fusion |
amount of heat energy required to melt exactly 1g of a solid substance at constant temperature |
| |
heat of vaporization |
amount of heat energy required to vaporize exactly 1g of a liquid substance at constant temperature |
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