For the O Chem one:
Always remember that phenols are about a million times more acidic than alcohols (due to resonance.)
Resonance increases acidity. Electron withdrawing groups increase acidity.
I believe ethanoic acid and ethanol are the same thing.....can someone back me up?
I don't know about methanol vs. ethanol honestly. Electron donating groups maybe....ethanol has more electron donating Carbons....electron donating reduces acidity. According to this reasoning (which could be wrong, please double check!) methanol is more acidic than ethanol.
For the General Chemistry one....you're dealing w/ salts:
NaCl is a neutral salt. NaOH (Strong Base) + HCl (Strong Acid) = Water + NaCl. When NaCl is dissolved in water....nothing happens....as far as acidity is concerned. They do disassociate into ions and conduct electricity. But Cl- is the conjugate base of a strong acid, so it's an extermely weak base. Na+ does nothing.
REMEMBER: the salt of a strong base and strong acid is neutral (pH =7)
Na2S
I don't know exactly how to tackle this one. It's the same idea, but S (-2) is the conjugate base of H2S (I would think)....you have to know if H2S is a strong or weak acid to figure out acidity.....I think it is a weak acid...based on that we have a salt of a strong base and weak acid. That would mean that S (-2) is the conjugate base of a weak acid, so it is a strong base. Bases attract H+, so the solution would have more OHs floating around, thus basic. (I'm guesssing....it all depends on if H2S is strong or weak. I had assumed weak...)
REMEMBER: the salt of a strong base and weak acid is basic (pH is greater than 7)
KBr....??
KOH + HBr
Strong Base + Strong Acid = Neutral pH
BF3
HF + B (OH)3 ?
HF = Weak Acid!!
B(OH)3 ??? I don't know?
So the idea is to figure out where the part same from, and if they are strong or weak.
If the come from a weak acid or base: then they are strong...(affect pH).
If the come from a strong acid or base: the are weak...(don't do much).
That's all I've got...hope it helps (also double check my question marks please or maybe someone else can verify.)
Good Luck w/ your studies.
