Achieve Week 10 #13

[Isabelle Rieke-Wey 2G]

Hi! Does anyone know how to do question 13 on the Achieve week 10 homework? Thanks!

[Maxwell Yao]

Hi,

For number 13 and 14 on the Achieve its useful to know how pKa and the solution pH determine whether the acid will stay neutral or will deprotonate (become charged).

If pH solution < pKa acid: solution is more acidic than acid, so acid remains protonated (neutral) as H—A
If pH solution > pKa acid: solution is more alkaline, and the acid will give off H+ to form A- and is negatively charged

Hope this helps.

[PatrickV]

We went over a chart in class that is a good visual tool of how to do these problems. At pH values above the pKA the there will be more charged species of the weak acid. At pH values below the pKA there will be more of the neutral species of HA. So for this problem the pKA (4.38) is greater than the pH (2.56), there will be more of the neutral species.