calculating protonation percentage

[Anna Turk 1D]

In some questions, such as achieve week 2 #5, it says to divide by Bformal, which is the sum of concentrations of the base and the conjugate, but others say to divide by Binitial. How do we know which one to use for each problem? Thanks!

[Ben Zhang 2H]

If it's protonation percentage, it should be concentration of conjugate divided by initial concentration of the molecule because we want to know how much of that initial concentration actually protonated.

[Michelle Jeong 1B]

Yes, I agree with Ben. To find % protanage, you do (the concentration of the conjugate / the initial concentration ) x 100.

[Savannah Licciardello 2C]

For this question it should be the conjugate/Binitial *100% as it wants to know what percentage of the original compound became the conjugate.