AP CHEM REVIEW THREAD

gonna try to structure this as a mix between the course at a glance chat and my class notes !!

spectroscopy:
•various types of radiation induce diff kinds of particle movement (translational, vibrational, rotational, electronic)
•spec. is used to determine relative % isotope abundance by using high voltage electric currents to excite particles
•analyzing the spikes in +

graphs can help determine which isotopes are the most naturally occurring!
•the y-axis is percent abundance, relative or otherwise, while the x-axis is M/Z (mass/charge)
•multiplying each mass by its percentage & then averaging out all the numbers = approx. molar mass on table

•protons and neutrons sum to MORE than the atomic mass, as some of their mass is inevitably converted to energy
•this is known as the atom's mass defect

reaction types!
•synthesis/comb. - combining elements (w/oxygen - COMBUSTION)
•decomp - one reactant breaking into various elements/compounds
•single disp. - 1 comp + element switch
•double disp. - 2+ compounds switch their anions
•organic combustion - carbon compound + O2

•neutralization - ahaha don't need to know acids and bases BUT keep those H+ donors/receivers definitions in mind i don't trust em
•metals/nonmetals + water - form bases & acids respectively!!

STRONG ACIDS: CLaire and BRian Invented Nutritious Candy they Sold for Profit

STRONG BASES: first column (Li, Na, K, Rb, Cs) + Sr & Ba

BOTH OF THESE will fully ionize/dissociate (why? ohoho wait til we meet IMFs)

they are also STRONG ELECTROLYTES & will conduct electricity WELL! (think weaker IMFs attracting & allowing charged particles to move through)

as for forming precipitates, weak bases & acids are more likely to do so as they have stronger IMFs & are less likely to dissolve!! we'll get into this more when IMFs roll around but for now, FRQs may ask about what precipitates indicate about the reaction in a roundabout way

oxidation # rules:
•net charge on all molecules is 0
•IA metals are all +1
•IIA metals are all +2
•aluminum is +3
•hydrogen is +1 (except when combined w alkali metals, then -1)
•fluorine is always -1, other halogens are usually -1
•oxygen is -2 except in peroxides + OF2

OXIDATION: an INCREASE in oxidation # by LOSING electrons

REDOX: a DECREASE in oxidation # by GAINING electrons

pneumonic: LEO the lion goes GER

redox balancing steps (NEUTRAL):
1. divide into 2 half-rxns, ox and redox
2. balance both sides for mass (coefficients)
3. balance for charge (add electrons to more positive side to match charge)
4. multiply each side to balance # of electrons on each side
5. add & check for m&z!

redox in ACID:
1-2 as above
3. balance oxygens by adding H2Os
4. balance hydrogen's by adding H+s
5. balance e-s, multiple to match them, add and check mass & charge!!

redox in BASE:
SAME AS ABOVE, except
6. add enough OH- ions to both sides to neutralize all H+s ions, bc what the fuck kinda base has extra H+ ions.... other than those headass amphoterics or w/e

STP conditions = 22.4 gaseous L per mole

determine limiting reactant by doing the stoich for the products from each component individually--whichever produces less is the limiting reactant (determine excess by calculating how much reactant IS used and subtract that from initial)

okay ill come back to this thread in the morning if i can cuz im falling jnto th throes of despair rn