Vocab Flashcards
Homogeneous solution
one phase or uniform throughout
solvent
the substance that causes some other substance to dissolve
solute
substance that dissolves or breaks apart
polar molecules
have positive and negative ends (partial)
can bond to ions in a crystal and can dissolve the ions
hydration
when water molecules completely surround the ions
solvation
when a solvent has completely surrounded the ion
electrolytes
substances that increase the conductivity of the water (Ionic compounds, acids)
strong electrolytes
electrolytes that dissociate 100%
conducts water very well
include ionic compounds and strong acids
weak electrolytes
electrolytes that ionize partially
weak acids and weak bases
non-electrolytes
dissolves in water but does not affect its conductivity
all polar compounds (alcohols, sugars, etc)
dynamic equilibrium
when the rate of crystalizing becomes equal to the rate of dissolving
saturated solution
when a solution has reached dynamic equilibrium.
when the rate of crystalizing becomes equal to the rate of dissolving
a solution in which the solvent can dissolve no more of a specific solute at a particular temperature
entropy
a measure of the randomness or disorder of a system
miscibile
liquids that completely dissolve in water in any amount
ex: methanol, ethanol, alcohol
partially miscible
liquids that only partially dissolve in each other
immiscible
liquids that do not dissolve in each other at all
supersaturated
A solution which contains a higher concentration of solute than does a saturated solution at that temperature. Not stable.
factors that impact rates of dissolving
Stirring
Increase in heat
Particle size
seed crystal
A small crystal (or speck of dirt, or dust) that is put into a supersaturated solution to begin the process of crystalization
solubility
Solubility is defined as the maximum quantity of a substance that can be dissolved in another.
non-polar
A nonpolar molecule has no separation of charge, so no positive or negative poles are formed. In other words, the electrical charges of nonpolar molecules are evenly distributed across the molecule. Nonpolar molecules tend to dissolve well in nonpolar solvents, which are frequently organic solvents.
ex: oil, gasoline, hexane
does not dissolve well in water
molarity
quantitative expression for the number of particles in solution
Basically concentration. number of moles in 1 litre of solution
mol/L
what happens to the moles in the new concentration and volume after diluting a solution?
it will have the exact same number of moles
why? I don’t know. It doesn’t make sense to me but It’s the law
what are the types of reactions in solution?
precipitation reactions
acid-base reactions
oxidation-reduction reactions
precipitation reaction
double-replacement reactions
reactants are always 2 aqueous solutions
the new combo of ions brings two ions of low solubility into contact with each other
process of precipitation
when 2 aqueous solutions mix together to form a solid
what is an acid?
substance that contains a hydrogen and a negative ion (anion) in aqueous solution
OR
substance that dissolves in water to produce hydrogen ions
what is a base?
a base is a chemical species that donates electrons, accepts protons, or releases hydroxide (OH-) ions in aqueous solution (this definition is from thoughtCO)
ORRR
a substance that contains a metal and hydroxide (ie NaOH)
acid-base reaction
dbl replacement reaction between an acid and a base
what did oxidation mean historically?
oxygen was added to a substance
what caused the change of the original definition of oxidation?
as atomic structure developed, it was realized that the metal atoms were being converted into positive metal ions (losing electrons)
substances other than oxygen (like Cl) can have this same effect on metal atoms!!
new definition of oxidation
the process at which a species loses electrons
historical definition of reduction?
when metals were being refined from metal ore
new definition of reduction
the gaining of electrons
was bc scientists realized that the reduction process actually involves giving electrons to metal ions to make them metal atoms
what is oxidation-reduction often referred to?
REDOX
oxidation numbers/states
the apparent “charges” on atoms when sharing equally or unequally in a covalent
process of dissolving something
polar water molecules have positive and negative ends, so they can bond to ions in a crystal. they can dissolve these ions
the water molecules surround the Ions, which is referred to as hydration
the more ions, the lower the…
freezing point
what kinds of compounds are electrolytes?
ionic compounds and acids
which phase is the most disorderly?
gas phase
how does temperature affect the amount of stuff dissolved into GAS
high temperature: dissolved gases coming OUT of solution
low temp: more gases being DISSOLVED
solubility decreases as temperature increases!
how does pressure affect solubility for liquids and solids
they cannot be compressed, so it has no affect
how does pressure affect solubility for GASES
can be compressed!! more molecules per unit volume at high pressure!
Can turn gas into aqueous!
think of soda!!
limiting reagent
in a precipitation reaction!
the reactant that ends up giving the least amount of product. basically, it limits what can be produced.
when does dissolving occur?
when solvent molecules collide with undissolved solute molecules or ions
the solvent bonds to the solute strongly enough to break the bonds between solute particles, drawing the solute into action
anything which increases the ____ between SOLUTE and SOLVENT will increases the ___
rate of collision
rate of dissolving
how does temperature increase rate of dissolving?
molecules higher kinetic energy
move faster as a result – greater rate of collision, harder collisions
how does particle size increase rate of dissolving?
SURFACE AREA increases!!
greater probability and frequency of collisions between solute and solvent
how does stirring increase rate of dissolving?
simply increases the RATE OF REPLACEMENT
brings fresh solvent into contact with the solution
consider a solution in which we have placed a small amount of salt into water. what types of interactions occur?
water to water – most likely
water to salt – causes dissolving, 2nd most likely
salt to salt/solute to solute – least likely but OMG CRYSTALIZATION
which factors impact SOLUBILITY?
stirring– NOPE
surface area–NOPE
Temperature– YES BECAUSE ENTROPY
relationship between temperature and entropy?
high temperatures favour more entropy, so favours dissolving of a oslid
oxidation state of a simple ion is?
the same as its charge
oxidation state of oxygen?
-2
exceptions for oxygen
H2O2 – oxidation number is -1
OF2 – oxidation number is +1
fluorine oxidation state
always -1
sum of oxidation state is?
neutral molecule – 0
polyatomic ion – equal to charge of the ion
