what is a bronsted-lowry acid?
donates protons (H+)
what is a bronsted-lowry base?
accepts protons (H+)
what makes a strong acid a strong acid?
-the propensity (tendency) to lose an acidic proton (forming an electron pair)
-the conjugate base is weak
what makes a strong base a strong base?
-the propensity to gain a proton (an electron pair attacks)
-the conjugate acid is weak
what are the six major electron stabilizing forces? briefly describe each.
- Polarizability- a larger atom can more easily stabilize electron density
- resonance- resonance moves electron density around, stabilizing it
- electronegativity- a more electronegative atom will “hold” electron density
- charge- having a charge inherently destabilizes electrons
- hybridization- the more s character, the closer electrons are to the nucleus
- inductive effects- the more dipoles pulling away from an atom with electrons, the less likely those electrons are to go forth and react
what do the most stable electrons correspond to?
the weakest base
what question should you ask when determining polarizability?
is the atom containing the electrons a row 3 or lower species?
what question should you ask when determining resonance?
is the atom containing the electrons able to participate in resonance?
what question should you ask when determining electronegativity?
is the atom containing the electrons highly electronegative (F, O, Cl)?
what question should you ask when determining charge?
is the atom containing the electrons uncharged?
what question should you ask when determining hybridization?
is the atom containing the electrons a sp-hybridized carbon?
what question should you ask when determining inductive effects?
are the dipoles pulling away from the atom containing the electron?
in acid base mechanisms, which molecule becomes the conjugate base?
an acid that donates a proton
in acid base mechanisms, which molecule becomes a conjugate acid
a base that accepts a proton
how do you predict the strength of acids?
-remove the most acidic proton (if you’re not sure, try comparing the conjugate bases when each proton is removed)
-determine available electron stabilizing forces acting on the electrons left behind (the earlier those forces acting upon the electrons, the more stable those electrons are)
-the most stable electrons correspond to the weakest base (and the strongest acid)
how do you predict the strength of bases? what is required for a compound to be a base?
-do not change the structure
-determine available electron stabilizing forces acting on the electrons (the earlier the forces acting upon the electrons, the more stable those electrons are)
-the most stable electrons correspond to the weakest base
-to be a base, a species must have a lone pair of electrons
how does polarizability stabilize?
larger atoms can stabilize electron desity more effectively
how does resonance stabilize?
resonance can delocalize electrons
how does electronegativity stabilize?
a more electronegative atom will “hold” electrons closer
how does charge stabilize?
a non-charged species will be more stable than a charged one
how does hybridization stabilize?
an sp hybridized carbon holds electrons close to the nucleus
how do inductive effects stabilize?
dipoles pulling away from an atom will reduce electron density
what do you do if multiple atoms have an equal electron stabilizing force in PRECHI?
-continue looking for the point of first difference
what is an exception to PRECHI?
-charge can overrule electronegativity in some cases
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Chromatography53
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PRECHI27
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extraction and functional groups in extraction53
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recrystallization32
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polarity and syllabus54
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isomerization and percent yield15
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liquid data and mass spectromotry41
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Infrared spectroscopy15
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substitution and simple distillation44
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microdistillation16
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unknown alcohol10
