[B] formal

[Fayola Obasi 1F]

Hey, can anyone explain how to calculate [B] formal ? I know it is the sum of the concentrations of B and BH+ but I am confused if its the sum of the Initial boxes or the Equilibrium boxes on the ICE table.

[kjwong02]

Hi! So, as you said, B formal is the sum of B and BH+. I didn't really use an ICE table for this problem because there was no given initial concentration. I found BH+ by figuring out the concentration of OH- because they are equal. I found OH- by taking the inverse log of pOH. I used the Kb= ((OH-)(BH+)/(B)) equation to find B, for we now know OH- and BH+ and Kb was given. I finally added the two concentrations I got! I hope this helps!

[Jessica Li 3H]

Hello!
I think it would be the sum of the equilibrium boxes of the ICE table. You are using [BH+], which is also how much the initial concentration of B changed during the reaction. You add [BH+] to [B], given as the initial concentration and assumed to change so little that it is about the same value at equilibrium. Thus, the formal concentration of B is the sum of B and BH+, which covers all concentrations of B that remained and reacted during the reaction.