## Chemistry 12th Edition

$NaOH 0.20M$ will have a higher pH.
When comparing 2 base solutions (with the same concentration), the one with the stronger base will have a higher concentration of $[OH^-]$. - In this case, since NaOH is stronger than $NH_3$, it will have a higher concentration of $[OH^-]$ With a higher concentration of $[OH^-]$, it will have a lower pOH. With a lower pOH, it will have a higher pH.