Strong and weak acids

• Strong acid


  Acid that ionizes completely, releasing all hydrogen ions
• Weak acid


  Acid that only partially ionizes, releasing some hydrogen ions
• pH


  Measure of the concentration of hydrogen ions in a solution
• As the concentration of hydrogen ions increases, the pH decreases</b>
• Each decrease of 1 on the pH scale represents the concentration of hydrogen ions increasing by a factor of 10
• Strong acid at any concentration

  Has a lower pH than a weak acid at the same concentration
• To get a low pH with a weak acid, it must be highly concentrated so that more of the acid particles ionize and release hydrogen ions
• Dissociation of hydrochloric acid

  H+ + Cl-
• Dissociation of nitric acid

  H+ + NO3-
• A hydrogen ion is a hydrogen atom that has lost an electron, so it is just a proton
• The ionization of a weak acid is reversible, forming an equilibrium between the undissociated and dissociated forms
• For a weak acid, the equilibrium lies towards the undissociated form, so only a small portion of the acid particles dissociate
• Weak acid


  A type of acid that only partially dissociates in water, meaning that only a fraction of the acid molecules release a hydrogen ion
• Undissociated form


  The form of an acid that still has all of its original components and has not released any hydrogen ions
• Dissociation


  The process by which a molecule separates into ions or smaller molecules when it is placed in a solution
• Equilibrium


  The state at which the rate of a reaction is equal to the rate of the reverse reaction, meaning that the concentrations of the reactants and products remain constant
• Small dissociation of weak acids

  For a weak acid, the equilibrium lies towards the undissociated form, so only a small portion of the acid particles dissociate and release a hydrogen ion