Is anyone in CHem 201 with Warren? Some reason I cant get the last problem that I ve been working on for ages!!! its # 6 in the webassign due tonight!..It's :

What volume (to the nearest 0.1 mL) of 4.80-M HCl must be added to 0.350 L of 0.300-M K2HPO4 to prepare a pH = 8.00 buffer?

I set up rxn table H3O+HPO4-->H20+H2PO4..........then I used the pH=pKa*log (base/acid) formula. So I got 6.16595=.105-x/4.8*x.......then solved for x and got 3.43 or 34.3. Can anyone tell me what Im doing wrong???? ASAP! Please! Thanks!

3/24/2006 9:07:15 PM

See this is why I dropped Warren's class. Motherfucker assigns HW on a friday night. Don't post this shit in the lounge either.

3/24/2006 9:15:30 PM

pH = pKa + log ([base]/[acid])

3/24/2006 9:16:58 PM

pH = pKa + log ([base]/[acid])

sorry, this is what I meant..I did it this way but not results!

3/24/2006 9:18:34 PM

bump

3/24/2006 9:29:38 PM

I was about to give you the answer

but then you put this shit in the lounge.

3/24/2006 9:44:10 PM

Yo man im stuck on the same stuff, i cant seem to get 5 or 6. They are set up the same but i cant get it.

3/24/2006 10:02:50 PM

sexy lil' slut you are.

3/24/2006 10:23:59 PM

What volume (to the nearest 0.1 mL) of 7.20-M NaOH must be added to 0.550 L of 0.200-M HNO2 to prepare a pH = 3.70 buffer?

Can anyone help with this one.

3/24/2006 10:41:53 PM

fuck some chemistry

3/24/2006 11:07:22 PM

it's just the henderson-hasselbach equation. You basically have everything except the concentration of acid. Plug and chug , once you have the concentration, then find the volume since 4.8 M is equal to 4.8 mol/L.

3/25/2006 12:33:54 AM