Chemistry test 2 Flashcards
molarity:
units: M
moles of solute/liter of solution
molality
units: m
moles of solute/kg of solvent
mas percent
solute of mass/total mass x 100
solution
a homogenous mixture of two or more substances
solvent
the principle component
colligative properties
property that depends on number of particles dissolved in solution, not on type of particle
saturated solution
solution in which the dissolved solute is in dynamic equilibrium with the solid solute
charge density
the higher it is, the better the hydration
lattice energy
energy that holds the crystal lattice together
heat of solution
can be exothermic or endothermic depends on the relative strengths of lattice energy (ion-ion) and hydrogen bonding in water compared to ion-dipole forces for the dissolved ions
aqueous solutions
have water as solvent, and a solid, liquid or gas solute
solubility
is amount of substance that will dissolve in given amount of solvent
entropy
measure of energy randomization or energy dispersed in a system
miscible
when the two substances are soluble and the three interactions within solution are of similar madnitude
enthalpy of solution
overall enthalpy change upon solution formation and is the sum of charges in enthalpy
heat of hydration
combination of enthalpy of the solvent and enthalpy of the mix
enthalpy change that occurs when one mole of gaseous solute ions are dissolved in water
recrystallization
common way to purify solid
mole fraction
amount of solute in mols/solute + solvent in mols
osmotic pressure
pressure required to stop osmotic flow
osmosis
flow of solvent from solution of lower solute concentration to higher solute concentration
van’t Hoff factor
ratio of moles of particles in solution to moles of formula units dissolved ( i )
surfactant
emulsifying agent
make micelles and cell walls
colloid
intermediate state between a solution and a suspension (ex: micelle)
suspension
an inhomogenous mixture that will eventually separate
rate of reaction
measure of how fast the reaction occurs
rate= - change in concentration of reactant/change in time
instantaneous rate of change
rate at any one point in time, represented by instantaneous slope of curve at that point
zero order reaction
units: M*s^-1
first order reaction
units: s^-1
second order reaction
units: M^-1*s^-1
integrated rate law
relationship between concentrations of reactants and time
half-life
time required for concentration of reactant to fall to one-half of its initial value
activation energy
the energy barrier for a reaction
frequency factor
number of times that the reactants approach the activation barrier per unit time (A)
collision theory
each approach to activation barrier is collision between reactant molecule
catalyst
substance that increases rate of chemical reaction but is not consumed by reaction
homogeneous catalyst
catalyst exists in same phase as reactants
heterogeneous catalyst
catalyst exists in phase different from reactants
kinetics
study of the rate of chemical reactions, fast or slow
thermodynamics
the study of how far a reaction will go, or if a reaction is favored
