Acids, Bases, and Salts

Daelin Buford

Acid-Base Theories

Arrhenius


  • Acids produce hydrogen ions (H^+) in aqueous solutions (HCl ----> H^+ - Cl^+)
  • Bases produce hydroxide ions (OH^-) when dissolved in water (NaOH ----> Na^+ + OH^-)

Bronsted-Lowry


  • Acid is a hydrogen-ion donor (H^+ or proton) (HCl is an acid)
  • "Conjugated acid" is the particle formed when the original base gains a hydrogen-ion
  • Base is hydrogen-ion acceptor (Water is a base)
  • "Conjugated base" is the remainder of the original acid, after it donates its' hydrogen-ion
  • NH3 + H2O ----> NH4^+ + OH^-

Lewis


  • Lewis Acid- electron pair acceptor
  • Lewis Base- electron pair donor

Calculating pH and pOH

[H^+]


  1. pH = -log[H^+]
  2. pOH = 14 - pH

pH



  1. [H^+] = 10^-pH

pOH



  1. [OH^-] = 10^-pOH



7 Strong Acids


  • Sulfuric Acid = H2SO4
  • Nitric Acid = HNO3
  • Hydrochloric acid = HCl
  • Hydrobromic acid = HBr
  • Hydroiodic acid = HI
  • Phosphoric acid = H3PO4
  • Acetic Acid = HC2H3O2



4 Strong Bases


  • Sodium Hydroxide = NaOH
  • Potassium Hydroxide = KOH
  • Barium Hydroxide = Ba(OH)2
  • Calcium Hydroxide = CaOH

Naming Acids, Bases, and Salts

Binary Acid


  • only two elements
  • first element is hydrogen
  • named--hydro______ic acid
  • HCl = hydrochloric acid

Ternary Acid



  • three elements
  • first element is hydrogen
  • other elements part of a polyatomic ion
  • naming does NOT require a prefix
  • ATE ----> IC
  • ITE ----> OUS
  • H2SO4 ----> sulfurIC acid
  • H2SO3 ----> SulfurOUS acid

Naming Bases and Salts

  • to name bases and salts, follow the standard rules for naming ionic compounds
  • NaOH = sodium hydroxide
  • CaCl2 = calcium chloride


Ka and Kb Expressions

Ka Expression


Ka = + -

(H ) (A )


Example

Equation: HNO2 ----> H^+ + NO2^-


Ka = [H^+] x [NO2^-]

[HNO2]


Kb Expression


Kb = (conjugate acid) x (OH^-)

(conjugate base)


Example


Kb = [M^+] [OH^-]

[MOH]

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