Buffers Knowledge-Based Download PDF

Questions

1. 1.

   Under which condition does a biological buffer solution demonstrate its maximum resistance to pH fluctuations when both acids and bases are introduced?

   • A) When the molar concentrations of the weak acid and its conjugate base are equal
   • B) When the concentration of the weak acid greatly exceeds the concentration of the conjugate base
   • C) When the weak acid completely dissociates into free hydronium ions in solution
   • D) When the conjugate base is present in high amounts while the weak acid is entirely depleted
2. 2.

   Which statement correctly defines the buffering capacity of an aqueous biological buffer system?

   • A) The fixed pH value at which a weak acid and its conjugate base reach dynamic chemical equilibrium
   • B) The amount of acid or base a buffer solution can absorb before experiencing a significant change in pH
   • C) The minimum volume of water required to dissolve equal molar amounts of a weak acid and its conjugate base
   • D) The rate at which water molecules self-ionize to replace neutralized hydronium ions in solution
3. 3.

   What primary chemical composition enables a biological buffer to resist drastic changes in hydrogen ion concentration?

   • A) A weak acid and its conjugate base present in dynamic equilibrium
   • B) Equal concentrations of a fully dissociated strong acid and strong base
   • C) A mixture of non-ionizable organic molecules such as neutral lipids
   • D) Pure water enriched solely with non-reactive neutral salts
4. 4.

   When a small amount of a strong base is added to an aqueous buffer solution, which process primarily prevents a sharp increase in pH?

   • A) The conjugate base directly binds excess hydroxide ions to form an insoluble precipitate.
   • B) Water molecules spontaneously dissociate to generate excess hydronium ions that neutralize the base.
   • C) Hydroxide ions displace hydrogen atoms within the conjugate base to neutralize the solution.
   • D) The weak acid component donates hydrogen ions that react with hydroxide ions to form water.
5. 5.

   How does a biological buffer system primarily resist a sharp decrease in pH when an acid is introduced into an aqueous solution?

   • A) The buffer contains a weak base component that binds excess hydrogen ions, removing them from free solution.
   • B) The buffer rapidly hydrolyzes neutral water molecules to increase the concentration of free hydroxide ions.
   • C) The buffer permanently neutralizes added protons by converting them into insoluble mineral salts that precipitate.
   • D) The buffer completely dissociates into strong conjugate electrolytes to drastically alter the electrical conductivity.