Chapter 7 - Solutions Flashcards
solvent
the substance present in greater amount
solutes
- spread evenly throughout the solution
- cannot be separated by filtration
- can be separated by evaporation
- are not visible, but can give a color to the solution
- the solute can be molecular or ionic and is dissolved in the solvent
the solute and solvent in a solution can be a combination between?
solid, liquid, and or gas
gas solutions
gas in a gas = air
O2(gas) + N(gas)
liquid solutions
gas in a liquid soda water CO2 + H20 and NH3 + H20
liquid in a liquid (vinegar) acetic acid and water
sollid in a liquid (seawater) NaCl + H20
iodine + alocohol
solid solutions
liquid in a solid = dental amalgam = mercury L + silver S
solid in a solid = Brass = Zn S + Cu S and Steel C S + Fe S
Factors that affect dissolving rate
- conditions that increase the mixing between solvent and solute increase that speed of solution formation
a. particle size
b. temperature
c. stirring/agitatioin
particle size
smaller crystals will have a larger surface to volume ratio
- smaller crystals will dissolve faster due to the increased solute-solvent contact
temperature (for solid)
at higher temperatures solvent molecules posses more kinetic energy (more movement)
- at higher temp solvent molecules will hit the crystal surfaces with more force and frequency
stirring/agitation
increases the solute - solvent contact
solubility
the maximum amount of solute that dissolves in a specific amount of solvent
- expressed as grams of solute in 100 grams of solvent usually water
g of solute
__________
100 g of water
solubility term for solid
soluble, slightly soluble, insoluble
solubility term for liquid
miscible, immiscible, partially miscible
Factors that affect solubility
Temperature
pressure
nature
temperature
- affects solubility
in general, the solubility of solids increases with increasing temperature
- sulobulity of gases decreases with increasing pressure
pressure ( gases)
- affect solubility
the solubility of gases increases with increasing pressure
nature of solute/solvent
- affect solubility
like dissolve like
Aqueous solution
solution in which water is the solvent
Water
- the most common solvent
- the most important solvent for life
- polar molecule
- forms hydrogen bonds between hydrogen atom in one water molecule and the oxygen atom in a different water molecule
- only ionic compounds and polar molecules are solute in water
What are soluble in water?
only ionic compounds and polar molecules
some ionic compounds, like NaCl dissolve very well in water at room temperature because of?
ion-dipole attraction
compounds that dissolve in a solvent are said to be? while those that do not are said to be?
soluble,
insoluble
the degree of solubility depends on?
the temperature
concentrated solutions
contains large amounts of solute
dilute solutions
contain small amounts of solute
unsaturated solutions
contain less than the maximum amount of solute
- can dissolve more solute
saturated solutions
contain the maximum amount of solute that can dissolve
- have un-dissolved solute at the bottom of the container
Concentration (equations)
C = Solute = amount of solute/ amount of solution
- percentage concentration: % m/m; m/v; v/v
- Molar concentration (molarity) M = mole of solute/L of solution
Isotonic solutions of iv fluids
NaCl = .9% m/v (saline)
5% glucose m/v
common solutions: percentage concentration
vinegar: .5% v/v
hydrogen peroxide H2O2 30% v/v
rubbing alcohol: isopropanol = 70% v/v
Dilution problems equation
C1V1 = C2V2
What happens when a solute dissolves in water?
individual solute particles are attracted to the surrounding water molecules
- they are pulled off and away from the solute
- when particles enter the solution, each solute particles are surrounded by water molecules (hydrated) and become insulated from one another
ionic compounds dissociate into?
cations and anions
- Ionization
molecular compounds dissolves into?
individual molecules
electrolytes
materials that dissolve in water to form a solution that will conduct electricity
nonelectrolytes
materials that dissolve in water to form a solution that will not conduct electricity
strong electrolytes
materials that dissolve completely as ions-only ions are present in solution - water soluble ionic compounds - strong acids - strong bases their solutions conduct electricity well
what are the strong acids?
HNO3 HClO4 H2SO4 HCl HBr HI
What are the strong bases?
LiOH KOH RbOH NaOH CsOH Sr(OH)2 Ba(OH)2 Ca(OH)2
weak electrolytes
materials that dissolve mostly as molecules, but partially as ions
- weak acids
- weak bases
- their solutions conduct electricity, but not well
acids
H-containing molecular compounds that ionize when they dissolve in water
when acids ionize, they form?
H+ and anions
- percentage of molecules that ionize varies from one acid to another
- acids that ionize virtually 100% are called strong acids
acids that only ionize a small percentage are called?
weak acids
acids that ionize virtually 100% are called?
strong acids
Dissociation Equation for strong electrolyties (soluble ionic compounds)
Kl(aq) ->
what happens when compounds containing a polyatomic ion dissolve
the polyatomic ion stays together
dissociated cations and anions are the?
species actually existing in the aqueous solution
dissolution equation for non-electrolytes
non-electrolytes are compounds that dissolve into molecules
- there is no ions in the aqueous solutions of nonelectrolytes
C12H22O11 -> C12H22O11
our body fluids, such as intra- and extra cellular fluids and blood are?
solutions containing many different cations and anions
Cat: Na, K, Ca, Mg
Ani: Cl, HCO3-, CO3^2-, PO4_3-
Equivalent Eq and milli-equavalent mEq
of Eq = charge of ions x mole of ion
1 Eq of Na+1 = 1mole x charge of Na = 1000mEq
the concentration of ions in body fluids are most conveniently expressed in terms of?
mEq/L
Electrolytes in body fluids
cations vs anions
must balance each other
if there is 155mEq/L of cations, there must be 155mEq/L of anions
what are the colligative properties of solutions?
- osmosis
- hypertonic, isotonic, and hypotonic solutions and the red blood cells
- dialysis
colligative properties of solutions
- the properties of a solvent change by?
the presence of solute molecules
the change in properties of colligative properties of solution depends on?
the number of particles (mole of solute) in a given amount kg of solvent and not on the nature or the mass of the particles
colligative properties of solutions
- adding 1 mole of Urea in water or any substance
- depresses freezing temperature - -1.86 C
- elevation of boiling temperature = 100.512 C
increases in osmolarity
osmosis
the passage of a solvent from a dilute solution (or pure solvent) across a semi-permeable membrane into a more concentrated solution
osmotic pressure
the pressure required to stop the net flow of solvent through the membrane
at equilibrium of osmotic pressure
there is no net movement of H2O and the liquid levels stabilize
the higher the solute concentration
the higher the osmolarity
the osmotic pressure is determined by?
relative number of impermeable solute particles on two sides of the semi-permeable membrane, not the nature of the solute particles
the outer most cell membrane
- plasma
- semipermeable membrane
- permeable to H20, urea, O2, and CO2
- not permeable to electrolytes and proteins
solution with the same osmotic pressure as the intracellular fluid of RBC is?
isotonic
hypertonic
solution with higher osmotic pressure
hypotonic
solutions with lower osmotic pressure
effect of solute concentration on tonicity of red blood cell
shrinking - crenation - hypertonic
swelling - hemolysis - hypotonic
no change - isotonic
osmosis in normal body function
- absorption of water by small intestine
- drinking sea water (3.5 NaCl) cause body to lose water rather than absorb it
conditions associated with osmolarity imbalance
- dehydration, over sweating
- over hydration
- drinking methanol (wood alcohol) or anti-freeze
reverse osmosis in water
purification/desalination
dialysis
- common lab technique for separating molecules in solution by the difference in theri rates of diffusion through a semipermeable membrane
- solvent and small solute particles pass through an artificial membrane; large particles are retained inside
- waste particles such as urea from blood are removed using hemodialysis
hemodialysis (artificial kidney)
artificial membrane with small pores that allow small waste molecules in the blood (urea, or other small waste metabolites) to diffuse out while retain large particles (platelet, red/white blood) cells and large molecules (plasma proteins)
homogenous mixture
two or more substances
- consists of a solvent an done or more solutes
