[oreoo]

What is the concentration of OH- ions in saturated limewater is [H3O+] = 3.98^-13 (to the negative thirteenth) M. Is limewater acidic, basic or neutral?

PLEASE HELP! I have a homework full of stuff like this due tomorrow.
I looked in my book and couldnt find anything. He showed us problems but not one like this. Can anyone help me please?

[Avex]

let me take a stab at this before i sleep
we can attempt to find pH through log

pH = -log[H+]

1 . -log[3.98^-13] = pH

something like that, then you found the pH.

then, you find the concentration of OH- by,

2. 14 = pH + pOH

we already know what pH is from step 1 (I didn't find the answer for the amount of pH since i have no calculator right now). so we solve for pOH.

3. once we find pOH, we solve for the concentration of OH-.

pOH = -log[OH-]

You do the log stuff (my mind is too tired to do that). and then you have found the concentration of OH-.
i dont have the answers right now cuz im too lazy, but hoped that solved ur question. i haven't done ap chem for a long time

+edit
oh yeah, can u post back or PM me for the answer. i wanna see if what i did was right, lol. i got a weird #, but it should be right