the pH scale

Cards (37)

  • pH scale
    Used to measure the strength of acids and bases and to determine which solution is more acidic or more basic (alkaline)
  • Acids
    Substances with a pH value less than 7
  • Bases/Alkalis
    Substances with a pH value greater than 7
  • Lower pH

    More acidic substance is
  • Higher pH

    Less acidic substance is
  • Lower pH
    Less basic/alkaline substance is
  • Higher pH
    More basic/alkaline substance is
  • PH increases
    Concentration of H<sup>+</sup> ions decreases
  • PH decreases
    Concentration of H<sup>+</sup> ions increases
  • PH increases
    Concentration of OH<sup>-</sup> ions increases
  • PH decreases
    Concentration of OH ions decreases
  • Neutral solution

    Concentration of H<sup>+</sup> ions is equal to OH<sup>-</sup> concentration
  • Water molecule
    Isn't ionic, but is able to ionize to a very small extent
  • Water ionization
    H₂O ⇌ H+ + OH-
  • Any water solution contains both hydrogen and hydroxide ions
  • Concentration of H+ (hydrogen ion)

    Inverse relationship with concentration of OH- (hydroxide ion)
  • pH
    Measure of the acidity or basicity of a solution
  • pH 7 is a neutral solution
  • Concentration of H+
    Decreases as pH increases
  • Concentration of OH-
    Increases as pH increases
  • In a pure/neutral solution, [H+] = [OH-]
  • Acidic solution

    [H+] > [OH-]
  • Basic solution
    [OH-] > [H+]
  • pH + pOH = 14 (always)
  • Calculating pH from [H+]
    pH = -log[H+]
  • pH is a logarithmic scale
  • Each pH unit change represents a 10-fold change in [H+]
  • The water molecule isn't ionic, but is able to ionize to a very small extent
  • Water ionization
    H2O + H2O ⇌ H3O+ + OH-
  • Any water solution contains both hydrogen and hydroxide ions
  • pH scale
    Measure of the acidity or basicity of a solution
  • Neutral solution has a pH of 7
  • Acidic solutions have a pH less than 7 (the lower the pH, the more acidic)
  • Basic solutions have a pH greater than 7 (the higher the pH, the more basic)
  • pH
    • log[H+]
  • Finding pH from pOH
    pH = 14 - pOH
  • pH is a logarithmic scale, each unit change represents a factor of 10 change in H+ concentration