ARIO Breakdown
Which is more acidic: H2O or NH3?
H2O
Atom: O is more electronegative than N, so it would stabilize the negative charge better
What is the conjugate base of H2SO4?
Where do curved arrows start from?
Electrons - bonds & lone pairs
Identify the Lewis Acid: BF3 + NH3 -> F3BNH3
BF3
It accepts the electrons from N
Lewis acids are always Bronsted-Lowry acids too.
Lewis acids don't need to have hydrogens
Which is the more stable base: phenoxide ion or methoxide ion?
Phenoxide
Resonance: the negative charge is delocalized, stabilizing the base
What is the conjugate acid of NH2- ?
NH3
Which bond breaks in acid-base reactions?
The bond between the acid and the proton
Which is the Lewis base: H2O + H+ -> H3O+
H2O
It is donating its lone pair to make a new bond
In ARIO, sp3 orbitals hold the negative charge better because there's 4 places to distribute it.
sp bonds are shorter, so the negative charge is closer to the positive nucleus and more stable
Which is the stronger acid: fluoroacetic acid or bromoacetic acid?
Fluoroacetic acid
Induction: fluorine is more electronegative than bromine, drawing the electrons away to stabilize the conjugate base
What is the counterion in NaC2H3O2?
Na+
How many arrows do you draw in Bronsted-Lowry reactions?
2
True or False: all Bronsted acids are also Lewis acids.
True
The acid that donates the H+ takes on a lone pair
Resonance always makes a base stronger.
Resonance stabilizes the negative charge on a base, making it weaker, not stronger
Which is more acidic: the proton on an alkyne or an alkene?
Orbital: sp hybridized carbon holds the lone pair closer to its nucleus, stabilizing the negative charge
True or False: the weaker the acid, the stronger the conjugate base.
True
Weak acids -> strong bases
Strong bases -> weak acids
Where does the longest arrow in acid-base reactions point toward?
The proton
How many arrows do you draw in Lewis reactions?
1
NH3 is more acidic than H2O because N is less electronegative and doesn't need H's electrons.
Acids give up protons but keep the electrons, so electronegative atoms would be more acidic
Rank them most to least acidic: NH3, H2O, HF
The atom electronegativity stabilizes the conjugate base
True or False: strong bases are more stable.
False
Weak bases are more stable. Strong = reactive. Weak = stable/unreactive
When OH- deprotonates H2O, where do the arrows go?
From the lone pair on OH- to the the hydrogen atom of H2O
From the old O-H bond to the oxygen in the water
What is the Lewis acid when H+ reacts with NH3?
H+
It accepts the electrons to make a new bond
Cl- is a strong base because its negative charge attracts positive protons.
Cl- is so electronegative that it doesn't want to share its electrons with other atoms