Studied by 13 people
limiting reactant
a reactant that:
-is totally consumed in a reaction
-limits the extent of the reaction
-determines the amount of product
A reaction stops when one reactant is used up. That reactant is the limiting reactant.
avogadro's number
6.02 x 10^23
mole
6.02 x 10^23 particles
representative particle (RP)
the particle being counted
molar mass
the mass in grams of one mole of a pure substance
moles to mass
number of moles x molar mass
m=nM
molar mass of a compound
the sum of the masses of the particles
that make up one mole of the compound
percent composition
the percent by mass of each element in a compound
molecular formula
the formula with subscripts that are the actual number of atoms
empirical formula
the formula with subscripts that are the smallest possible whole-numbers
hydrate
a compound that has a specific number of water molecules bound to its atoms
naming hydrates
“compound” & “prefixhydrate” formula is AX•nH20
Uses of Hydrates
Na₂SO₄∙10H₂O is used to store solar energy
stoichiometry
the study of quantitative relationships among reactants and products
mole ratio
the ratio between any two substances in a balanced chemical equation
finding mole ratio
4Fe(s)+3O₂(g)→2Fe₂O₃(s)
ratio of number of moles of Fe2O3 to mo moles of Fe
excess reactant
a reactant that remains after the reaction stops
theoretical yield
the maximum amount of product that can be produced from a given amount of reactant
actual yield
the amount of product produced when the chemical reaction is carried out in an experiment
percent yield
ratio of actual yield to theoretical yield
kinetic molecular theory
describes behavior of matter in terms of particles in motion
features of kmt (kinetic molecular theory)
1. tiny particles in lots of empty space
2. straight line motion until they collide with each other or with the walls of the container
3. collisions are elastic
4. temperature is a measure of kinetic energy
elastic collision
a collision in which no kinetic energy is lost
temperature
a measure of the average kinetic energy of the particles in a sample
diffusion
the movement of one material through another from an area of high concentration to an area of low concentration
pressure
force per unit area
gas behavior
space between gas particles decreases as gas compresses.
space between gas particles increases as gas expands.
atmosphere
equals 14.7 psi, or 760 mmHg
pascal
1N/m^2
barometer
an instrument used to measure atmospheric pressure
manometer
an instrument used to measure vapor pressure of a substance
daltons law of partial pressures
total pressure of a mixture of gas is the sum of the pressures of all the gasses in the mixture Ptotal=P1+P2+P3+...Pn
dipole-dipole force
attraction between oppositely charged regions of polar molecules=medium
london dispersion force
weak force resulting from temporary shifts in the density of electrons in the electron cloud=weak
hydrogen bond
A strong dipole-dipole attraction between molecules that contain a hydrogen atom bonded to a small, highly electronegative atom formed only by an H atom bonded to N, O, or F atoms
intramolecular forces
Hold atoms or ions together within a molecule
intermolecular forces
Hold molecules to each other.
(dipole dipole and london and hydrogen bond)
viscosity
resistance to flow
surface tension
the energy required to increase the surface area of a liquid
allotrope
One of two or more forms of an element with different structures in the same state of matter.
Amorphous solid
A solid whose atoms, ions, or molecules are not arranged in a regular repeating pattern.
Melting point
The temperature at which a crystalline solid becomes a liquid
vaporization
The process by which a liquid changes to a gas or vapor
Boiling point
The temperature at which a liquid becomes a gas
Vapor pressure
The pressure exerted by a vapor over a liquid
evaporation
Vaporization occurring only at the surface of a liquid.
boiling
Vaporization occurring throughout a liquid
sublimation
The process by which a solid changes directly to a gas without first becoming a liquid.
properties of solids
shape: definite \n volume: definite \n expansion on heating: small \n compressibility: no
properties of liquids
particles flow, vaporization, definite volume, assumes the shape of the container, condensed phase, IMFs present disorder of particles
properties of gases
expand to volume of the container, highly compressible, form homogenous mixtures, IMFs nonexistentfc
condensation
The process by which gas becomes a liquid
Freezing point
The temperature at which liquid becomes a crystalline solid
deposition
The process by which substance changes from a gas into a solid without first becoming a liquid.
Phase diagram
A graph of pressure versus temperature that shows the phases of a substance
Triple point
The T and P where solid, liquid, and gas can coexist
six phase changes
melting, vaporizing, condensation, freezing, sublimation, deposition
phase changes that require energy
melting, vaporization, sublimation.
phase changes that release energy
freezing, condensation, deposition.
Critical point
The temperature above which a substance cannot exist at a liquid.
normal melting point
melting point at a pressure of 1 atmosphere
normal boiling point
the temperature at which the vapour pressure is equal to the standard sea-level atmospheric pressure
cohesion
force of attraction between identical molecules
adhesion
force of attraction between molecules that are different
surfactant
A compound that lowers the surface tension of water
Crystalline solid
A solid whose atoms, ions, or molecules are arranged in an orderly, geometric structure
Unit cell
The smallest arrangement of atoms in a crystal lattice that has the same symmetry as the entire pattern of lattice
boyles law
P₁V₁ = P₂V₂
absolute zero
the lowest possible theoretical temperature
charles's law
V1/T1 = V2/T2
gay-lussac's law
P₁/T₁=P₂/T₂
combined gas law
P₁V₁/T₁ = P₂V₂/T₂
avogadro's principle
equal volumes of gases at same T & P have same number of particles
molar volume
the volume that 1 mole of gas occupies at STP
standard temperature and pressure (STP)
0˚C and 1 atm, 22.4L
ideal gas constant (R)
an experimentally determined constant whose value
depends on the units for pressure (should be given on the test)
ideal gas law
PV = nRT
heterogeneous mixture
a mixture that does not have uniform composition and in which the individual substances remain distinct
suspension
a heterogeneous mixture containing particles that settle out if left undisturbed
thixotropic mixture
a heterogeneous mixture that is viscous at rest but flows when agitated
colloid
a heterogeneous mixture of intermediate-sized particles that do not settle out
dispersion medium
the most abundant substance in a colloid (usually water)
dispersed particles
particles that do not settle out of a colloid
brownian motion
erratic, random movement of dispersed particles caused by collisions with the dispersion medium.
tyndall effect
the scattering of light by dispersed colloid particles
homogeneous mixture:
a mixture that has uniform composition throughout
solution
another word for homogeneous mixture
solute
a substance dissolved in a solution
solvent
the substance that dissolves a solute
soluble
describes a substance that can be dissolved in a solution
insoluble
opposite of soluble
miscible
describes two liquids that are soluble in each other
immiscible
opposite of miscible
mixture
a combination of two or more pure substances that retain their individual chemical properties
concentration
a measure of how much solute is dissolved in a specific amount of solvent or solution
percent by mass
Mass of solute/mass of solution times 100
percent by volume
volume of solute/volume of solution times 100
mole fraction
moles of A/moles of A plus moles of b
molarity
moles of solute/liters of solution times 100
dilution equation
to dilute from concentrated solution to less concentrated solution. M1V1=M2V2
Note 
Flashcard (22)