A buffer in seawater is often modeled by the conjugate pair HPO /PO
CHEMISTRY · Multi-part · A Level · Chemistry · Acids and bases · Acids and bases
Problem
A buffer in seawater is often modeled by the conjugate pair HPO42−/PO43−. Consider 100.0 mL of a solution that is 0.20 M in each species.
A researcher investigates how the buffer responds to two different additions.
(a) When 5.0 mL of 1.0 M NaOH is added, write the balanced net ionic equation that describes the reaction occurring in the buffer.
(b) When 5.0 mL of 1.0 M HCl is added to a fresh 100.0 mL sample of the same buffer, write the balanced net ionic equation that describes the reaction.
(c) Compare the conjugate acid–base roles of HPO42− and PO43− in parts (a) and (b), citing evidence from the equations you wrote.