UNIT 4: Aqueous solutions ((4.1) PROPERTIES (SOLUBILITY RULES: (Group…
UNIT 4: Aqueous solutions
Water is polar, so its relatively negative/positive ends will separate a dissociable molecule and the negative O end will attach to the cation while the positive H ends will attach to the anion. They also can move freely, meaning they will disperse throughout solution evenly. (SOLVATED.)
If something is soluble and dissociates, it is a strong electrolyte. If only one is true, it may be weak (or a strong base?) and if neither are true, then it is a non-electrolyte. .
if it is a soluble ionic, it is a strong electrolyte; if it as a molecular, it must be a strong base/acid or acetate or else it is weak.
Group 1/ammonium, nitrates, bicarbonates, and chlorates are always soluble. (and acetate???)
Chlorides, Iodides, Bromides soluble unless w/Silver or Lead.
Sulfates are soluble unless w/silver, lead, calcium, barium, or strontium (above plus last 3.)
Insolubility rules: (always soluble overrules these)
Hydroxides (bases), Carbonates, sulfides, phosphates, chromates (except for group 2 + sulfides)
4.2-4.3 METATHESIS (ACID-BASE AND PRECIPITATION)
AX + BY --> AY + BX (anions/cations switch)
NET IONICS: write molecular, split eq. up into anions/cations, cancel out any molecules found on both sides that 1. have same coefficient and 2. same state symbol.
if EVERYTHING is a spectator, NO REACTION WILL OCCUR!!
need to know solubility rules!!! for which products are solid
Exceptions: (neutralization reactions)
If the first molecule is an acid and the second is a sulfide, then it makes H2S gas as a product.
If an acid and a carbonate/hydro, will produce salt, water, and CO2 gas. (first makes carbonic acid?)
Any reaction w/transfer of electrons. OIL RIG!
JUST DETERMINE ON's on both sides to be safe.
Monatomic ions have ON of their charge.
ONs of metals are the group #.
Standalone elements have ON of 0.
Nonmetals' charges usually group associated but..*
a. ON of F is always -1. (MOST ELECTRONEGATIVE/GREEDY)
b. ON of all halogens is -1 unless bonded to F.
c. O is always -2 unless bonded to F or in peroxide where -1 (H2O2 only peroxide for now)
d. H is +1 when w/nonmetals, -1 when w/metals.
Sum of all ON's is 0 if neutral, or the charge of polyatomic
MOLARITY: moles/L. unit of concentration... conversion factor b/n moles, Ls, and molarity.
M1V1 = M2V2. In other words, first reach moles in desired dilution, then figure out how many Ls that is of stock solution (by dividing that by the molarity of stock.)
Titrations: where an indicator is added to an acid/a base, and once it's neutralized, the indicator will change color. Now you have a volume value of known molarity of standard solution. Use that to calculate moles used, and using balanced equation, acquire moles of the unknown and divide that by volume of unknown in the flask.