Acids and Bases Flashcards
Lewis Acid
Accepts pair of e-
Lewis Base
Donates pair of e-
Arrhenius Acid
Produces H+ in water
Arrhenius Base
Produces OH- in water
Bronstead-Lowry Acid
Donates H+
Bronstead-Lowry Base
Accepts H+
Acid Strenght
Weaker bond = more acidic
More polar = more acidic
Strong Acids
HI, HBr, HCl, HNO3, HClO4, HClO3, H2SO4
Strong Bases
NaOH, KOH, NH2-, H-, Ca(OH)2, Na2O, CaO
Weak Acids
HF, HCN, CH2COOH (acetic acid), H20
Weak Bases
NH3, NH4OH, C5H5N (pyridine), H20
Hydrides as Acids/Bases
Basic to the left (Na+) and acidic to the right (H2S)
Metal hydrides basic or neutral
Non-metal hydrides acidic or neutral
Acidity increases down the period
Conjugate acids and Conjugate bases
HA + H20 H3O+ (conj acid) + A- (conj base)
Strong acids have weak conj bases
weak acids have strong conj bases
pH
pH=-log[H+]
Amino acids/ organic acids
Amphoteric: act as acid or base dep on environment
weak CH3-CH3
Autoionization of Water
Kw=[H3O+][OH-] Kw=10^-14
pKw= pH + pOH pH + pOH = 14
Acid dissociation constant Ka
Ka=[H3O+][A-]/[HA]
pKw= pKa + pKb = 14
Equilibrium constant of conj base Kb
Kb=[OH-][HA]/[A-]
pH Trends
larger Ka= smaller pKa = lower pH
Ka>1 or pKa
Titration Neutralization
Acid + Base -> Water + Salt
Highly exothermic
Equivalence Point
Mid point (almost verticle)
Equal equivalents of acid and base
Strong acid-weak base: equivalence above 7
Half-equivalence point
point where 1/2 of acid has been neutralized by base
Most horizontal point
Equals pKa of weak acid
pH=pKa + log [H-]/[HA]
Weak acid-weak base titration
pH range more compressed
acid>base pH below 7
acid
Indicatiors
Weak acid whose conj base is a different color
pKa close as possible to pH of the titration’s equivalence point
