Chapter 4.3, Problem 4.14BFP

Interpretation Introduction

Interpretation:

The mass of acetylsalicylic acid that is needed to react with $14.10\text{mL}$ of $0.128M\text{ NaOH}$ is to be calculated.

Concept introduction:

Strong acids and strong bases are the substance that dissociates completely into its ions when dissolved in the solution. They dissociate completely in water to release ${\text{H}}^{+}$ ions and ${\text{OH}}^{-}$ ions.

Weak acids and weak bases are the substance that does not dissociate completely into its ions when dissolved in the solution. They dissociate partially in water to release ${\text{H}}^{+}$ ions and ${\text{OH}}^{-}$ ions.

Acetylsalicylic acid $\left({\text{HC}}_9{\text{H}}_7{\text{O}}_4\right)$ is a weak acid and sodium hydroxide $\left(\text{NaOH}\right)$ is a strong base. Sodium hydroxide $\left(\text{NaOH}\right)$ dissociates completely into its respective ions. Acetylsalicylic acid $\left({\text{HC}}_9{\text{H}}_7{\text{O}}_4\right)$ dissociates to some extent and gives only one ${\text{H}}^{+}$ for the reaction. They both react to form ${\text{NaC}}_9{\text{H}}_7{\text{O}}_4$ and a water molecule.

The molecular equation for the acid-base reaction of acetylsalicylic acid and sodium hydroxide is:

${\text{HC}}_9{\text{H}}_7{\text{O}}_4\left(aq\right)+\text{NaOH}\left(aq\right)\to {\text{NaC}}_9{\text{H}}_7{\text{O}}_4\left(aq\right)+{\text{H}}_2\text{O}\left(l\right)$