Skip to main content
Back

Principal Species quiz

Control buttons has been changed to "navigation" mode.
1/15
  • What does the acid dissociation constant (Ka) indicate about an acid?
    Ka indicates the strength of an acid; a higher Ka means a stronger acid.
  • What does it mean if Ka is greater than 1?
    If Ka > 1, the acid is considered strong.
  • What does it mean if Ka is less than 1?
    If Ka < 1, the acid is considered weak.
  • How can you use pKa to determine the principal species in a solution?
    By comparing the solution's pH to the acid's pKa, you can determine whether the acidic or basic form predominates.
  • What happens when pH is less than pKa for a monoprotic acid?
    The acidic form predominates over the basic form.
  • What happens when pH is greater than pKa for a monoprotic acid?
    The basic form predominates over the acidic form.
  • At what point do the acidic and basic forms exist in equal concentrations?
    When pH equals pKa, both forms exist in equal concentrations (50% each).
  • What is the principal species when pH equals pKa?
    Both the acidic and basic forms are present at 50% each.
  • How does increasing the pH above the pKa affect the principal species?
    The basic form becomes the principal species.
  • How does decreasing the pH below the pKa affect the principal species?
    The acidic form becomes the principal species.
  • What are the two forms considered when discussing principal species for acids?
    The acidic form (HA) and the basic form (A−).
  • Can the relationship between pH and pKa be applied to polyprotic acids?
    Yes, the relationship applies to diprotic and polyprotic acids as well.
  • What does the dividing line between acidic and basic forms represent?
    It represents the pKa value, where both forms are present in equal amounts.
  • Why is converting Ka to pKa useful?
    It allows easier comparison with the solution's pH to determine the predominant species.
  • What does the acid dissociation constant (Ka) numerically represent?
    It represents how easily an acidic hydrogen can be removed from the acid.