51 terms

Chem Exam

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true formula
the actual number of atoms in a compound.
empirical formula
CH3 is an example of an
molecular formula
C2H6 is an example of an
empirical formula
the simplest ratio
compressed
Gases are easily __________.
pressure, volume, temperature and amount
What four variables describe a Gas?
kilopascals
What is the common unit of pressure?
liters
What is the common unit of volume?
Kelvin
What is the common unit of temperature?
moles
What is the common unit for amount?
high / low
Gases naturally move from areas of ____ pressure to ___ pressure.
directly
Pressure and the number of molecules are _________ related.
increases
As volume decreases, pressure __________.
pressure
Raising the temperature of a gas increases the _______, if the volume is held constant.
Boyle's Law
Gas pressure is inversely proportional to the volume when temperature is held constant. (Whose law?)
P1V1 = R2V2
Boyle's Law's equation?
Charle's Law
The volume of a fixed mass is directly proportional to the Kelvin temperature when pressure is held constant.(Whose law?)
Kelvin
Gas law problems involving temperature will always require that the temperature be in ________.
Gay Lussac's Law
The pressure and Kelvin temperature of a gas are directly proprtional, provided that the volume remains constant. (Whose law?)
The Combined Gas Law
_____________ expresses the relationship between pressure, volume and temperature of a fixed amount of gas.
Boyle's Law
If the temperature remains constant use...
Charle's Law
If the pressure remains constant use...
Gay-Lussac's Law
If the volume remains constant use...
molar volume
the volume occupied by a mole of any gas at STP
molar mass
the mass of a mole of any element or compound
atomic mass
the number of grams of an element is numerically equal to the atomic mass of the element in amu
Avogadro's number
the number of representative particles of a substance in 1 mole of that substance
representative particle
an atom, an ion, or a molecule, depending upon the way a substance commonly exists
mole
the SI unit used to measure each amount of substance
standard temperature and pressure
0 degrees celsius and 1 atm
percent composition
the percent by mass of each element in a compound
empirical formula
the smallest whole number ratio of the atoms in a compound
number of molecules
this quantity can always be used in the same way as moles interpreting balanced chmical equations
volume
this is conserved in reactions where the temperature is constant and the number of moles of gaseous reactants is the same as that of gaseous products
mass
this is conserved in every ordinary chemical reaction
limiting reagent
the reactant that determines the amount of product that can be formed in a reaction
theoretical yield
the maximum amount of product that could be formed from given amounts of reactants
excess reagent
the reactant that is not completely used up in a reaction
actual yield
the amount of product formed when a reaction is carried out in the laboratory
percent yield
the ratio of the actual yield to the theoretical yield
evaporation
vaporization at the surface of a liquidthat is not boiling
vaporization
the conversion of a liquid to a gas below the boiling point
boiling point
the temperature at which the vapor pressure of a liquid is equal to the external pressure
normal boiling point
the temperature at which the vapor pressure of a liquid is equal to 1 atmosphere
melting point
the temperatre at which a solid changes into a liquid
sublimation
the change of a solid directly to a vapor
kinetic theory
all matter consists of tiny particles that are in constant motion
kinetic theory
the energy an object has due to its motion
barometer
a device used to measure atmospheric pressure
atmospheric pressure
the pressure resulting from the collision of atoms and molecules with objects
vapor pressure
a measure of the force exerted by a gas above a liquid