Chapter 19, Problem 19.51P

As we will see in Chapter $23$, $\text{C}-\text{H}$ bonds are sometimes more acidic than $\text{O}-\text{H}$ bonds. Explain why the $\text{p}{K}_{\text{a}}$ of ${\text{CH}}_{\text{2}}{\left(\text{CHO}\right)}_{\text{2}}$ is lower than the $\text{p}{K}_{\text{a}}$ of $\text{OH}{\left({\text{CH}}_{\text{3}}\right)}_{\text{3}}\text{OH}$ ( $9$ vs. $16$).